Zig 0.15 (#9004)

Replaces #8372 Before merge I'm going to squash this and give @pluiedev coauthor, since I took a lot of her work. I just have to go through this myself to make sure I learn all the changes in Zig 0.15, but as I got things, I copy and pasted her work in. My work is probably less thorough and there are places we can convert deprecated things, probably, but this results in green CI. ## Benchmarks It looks like there are some speed regressions in isolated places. I'm not sure if this is noise or not, I'm going to keep running some tests. If someone can check macOS that'd be helpful (my vtebench is down on macOS atm), cc @qwerasd205 if interested. On an x86_64 system: ![output](https://github.com/user-attachments/assets/25395c18-2560-45c8-9fd3-d524bc5cbfb8)
2025-10-09 03:16:33 +00:00 · 2025-10-03 07:12:12 -07:00
parent dfa2354fec 569fe92389
commit e0cf528576
183 changed files with 2574 additions and 2217 deletions
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,7 +14,6 @@ jobs:
      - build-dist
      - build-examples
      - build-flatpak
-      - build-freebsd
      - build-libghostty-vt
      - build-linux
      - build-linux-libghostty
@@ -333,7 +332,7 @@ jobs:
        run: nix build .#ghostty-releasefast

      - name: Check version
-        run: result/bin/ghostty +version | grep -q 'builtin.OptimizeMode.ReleaseFast'
+        run: result/bin/ghostty +version | grep -q '.ReleaseFast'

      - name: Check to see if the binary has been stripped
        run: nm result/bin/.ghostty-wrapped 2>&1 | grep -q 'no symbols'
@@ -342,7 +341,7 @@ jobs:
        run: nix build .#ghostty-debug

      - name: Check version
-        run: result/bin/ghostty +version | grep -q 'builtin.OptimizeMode.Debug'
+        run: result/bin/ghostty +version | grep -q '.Debug'

      - name: Check to see if the binary has not been stripped
        run: nm result/bin/.ghostty-wrapped 2>&1 | grep -q 'main_ghostty.main'
@@ -513,7 +512,7 @@ jobs:
          $fileContent = Get-Content -Path "build.zig" -Raw
          $pattern = 'buildpkg\.requireZig\("(.*?)"\);'
          $zigVersion = [regex]::Match($fileContent, $pattern).Groups[1].Value
-          $version = "zig-windows-x86_64-$zigVersion"
+          $version = "zig-x86_64-windows-$zigVersion"
          Write-Output $version
          $uri = "https://ziglang.org/download/$zigVersion/$version.zip"
          Invoke-WebRequest -Uri "$uri" -OutFile ".\zig-windows.zip"
@@ -1138,6 +1137,7 @@ jobs:
    name: Build on FreeBSD
    needs: test
    runs-on: namespace-profile-mitchellh-sm-systemd
+    if: false # FIXME: FreeBSD does not yet ship with Zig 0.15
    strategy:
      matrix:
        release:
--- a/build.zig
+++ b/build.zig
@@ -4,7 +4,7 @@ const builtin = @import("builtin");
 const buildpkg = @import("src/build/main.zig");

 comptime {
-    buildpkg.requireZig("0.14.0");
+    buildpkg.requireZig("0.15.1");
 }

 pub fn build(b: *std.Build) !void {
@@ -249,8 +249,6 @@ pub fn build(b: *std.Build) !void {
    {
        const mod_vt_test = b.addTest(.{
            .root_module = mod.vt,
-            .target = config.target,
-            .optimize = config.optimize,
            .filters = test_filters,
        });
        const mod_vt_test_run = b.addRunArtifact(mod_vt_test);
@@ -258,8 +256,6 @@ pub fn build(b: *std.Build) !void {

        const mod_vt_c_test = b.addTest(.{
            .root_module = mod.vt_c,
-            .target = config.target,
-            .optimize = config.optimize,
            .filters = test_filters,
        });
        const mod_vt_c_test_run = b.addRunArtifact(mod_vt_c_test);
@@ -280,6 +276,8 @@ pub fn build(b: *std.Build) !void {
                .omit_frame_pointer = false,
                .unwind_tables = .sync,
            }),
+            // Crash on x86_64 without this
+            .use_llvm = true,
        });
        if (config.emit_test_exe) b.installArtifact(test_exe);
        _ = try deps.add(test_exe);
@@ -289,7 +287,7 @@ pub fn build(b: *std.Build) !void {
        test_step.dependOn(&test_run.step);

        // Normal tests always test our libghostty modules
-        test_step.dependOn(test_lib_vt_step);
+        //test_step.dependOn(test_lib_vt_step);

        // Valgrind test running
        const valgrind_run = b.addSystemCommand(&.{
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -3,54 +3,55 @@
    .version = "1.2.1",
    .paths = .{""},
    .fingerprint = 0x64407a2a0b4147e5,
-    .minimum_zig_version = "0.14.1",
+    .minimum_zig_version = "0.15.1",
    .dependencies = .{
        // Zig libs

        .libxev = .{
            // mitchellh/libxev
-            .url = "https://github.com/mitchellh/libxev/archive/7f803181b158a10fec8619f793e3b4df515566cb.tar.gz",
-            .hash = "libxev-0.0.0-86vtc2UaEwDfiTKX3iBI-s_hdzfzWQUarT3MUrmUQl-Q",
+            .url = "https://github.com/mitchellh/libxev/archive/34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz",
+            .hash = "libxev-0.0.0-86vtc4IcEwCqEYxEYoN_3KXmc6A9VLcm22aVImfvecYs",
            .lazy = true,
        },
        .vaxis = .{
            // rockorager/libvaxis
-            .url = "git+https://github.com/rockorager/libvaxis#1f41c121e8fc153d9ce8c6eb64b2bbab68ad7d23",
-            .hash = "vaxis-0.1.0-BWNV_FUICQAFZnTCL11TUvnUr1Y0_ZdqtXHhd51d76Rn",
+            .url = "https://github.com/rockorager/libvaxis/archive/9fc9015d5f147568e18c5e7ca28f15bf8b293760.tar.gz",
+            .hash = "vaxis-0.5.1-BWNV_O8fCQAeUeVrESVc-2BdXloEXkFqReDJL7Q6XTSZ",
            .lazy = true,
        },
        .z2d = .{
            // vancluever/z2d
-            .url = "https://github.com/vancluever/z2d/archive/refs/tags/v0.8.1.tar.gz",
-            .hash = "z2d-0.8.1-j5P_Hq8vDwB8ZaDA54-SzESDLF2zznG_zvTHiQNJImZP",
+            .url = "https://github.com/vancluever/z2d/archive/a1237f6881d99b75abd8a20a934e62e34b44a005.tar.gz",
+            .hash = "z2d-0.8.2-pre-j5P_HlVRFgCsBTQ3EgUoKbYHx5JMnyH1mHsOSPiafnef",
            .lazy = true,
        },
        .zig_objc = .{
            // mitchellh/zig-objc
-            .url = "https://github.com/mitchellh/zig-objc/archive/c9e917a4e15a983b672ca779c7985d738a2d517c.tar.gz",
-            .hash = "zig_objc-0.0.0-Ir_SpwsPAQBJgi9YRm2ubJMfdoysSq5gKpsIj3izQ8Zk",
+            .url = "https://github.com/mitchellh/zig-objc/archive/f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz",
+            .hash = "zig_objc-0.0.0-Ir_Sp5gTAQCvxxR7oVIrPXxXwsfKgVP7_wqoOQrZjFeK",
            .lazy = true,
        },
        .zig_js = .{
            // mitchellh/zig-js
-            .url = "https://deps.files.ghostty.org/zig_js-12205a66d423259567764fa0fc60c82be35365c21aeb76c5a7dc99698401f4f6fefc.tar.gz",
-            .hash = "N-V-__8AAB9YCQBaZtQjJZVndk-g_GDIK-NTZcIa63bFp9yZ",
+            .url = "https://github.com/mitchellh/zig-js/archive/04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz",
+            .hash = "zig_js-0.0.0-rjCAV-6GAADxFug7rDmPH-uM_XcnJ5NmuAMJCAscMjhi",
            .lazy = true,
        },
        .uucode = .{
-            .url = "https://github.com/jacobsandlund/uucode/archive/190706c6b56f0842d29778007f74f7d3d1335fc5.tar.gz",
-            .hash = "uucode-0.1.0-ZZjBPpAFQABNCvd9cVPBg4I7233Ays-NWfWphPNqGbyE",
+            // TODO: currently the use-llvm branch because its broken on self-hosted
+            .url = "https://github.com/jacobsandlund/uucode/archive/f81f8ef8518b8ec5a7fca30ec5fdbc76cc6197df.tar.gz",
+            .hash = "uucode-0.1.0-ZZjBPjQHQADuCy1VMWftjrMl3iWqgMpUugWVQJG6_7xT",
        },
        .zig_wayland = .{
            // codeberg ifreund/zig-wayland
-            .url = "https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz",
-            .hash = "wayland-0.4.0-dev-lQa1kjfIAQCmhhQu3xF0KH-94-TzeMXOqfnP0-Dg6Wyy",
+            .url = "https://codeberg.org/ifreund/zig-wayland/archive/1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz",
+            .hash = "wayland-0.5.0-dev-lQa1khrMAQDJDwYFKpdH3HizherB7sHo5dKMECfvxQHe",
            .lazy = true,
        },
        .zf = .{
            // natecraddock/zf
-            .url = "https://github.com/natecraddock/zf/archive/7aacbe6d155d64d15937ca95ca6c014905eb531f.tar.gz",
-            .hash = "zf-0.10.3-OIRy8aiIAACLrBllz0zjxaH0aOe5oNm3KtEMyCntST-9",
+            .url = "https://github.com/jcollie/zf/archive/52ad2e5528ab754f77437edf08a07b5ec843661c.tar.gz",
+            .hash = "zf-0.10.3-OIRy8QGJAACJcu3tCGtfbJnnd3Y4QL7OW_X8PJ8u_ASR",
            .lazy = true,
        },
        .gobject = .{
--- a/build.zig.zon.json
+++ b/build.zig.zon.json
@@ -64,10 +64,10 @@
    "url": "https://deps.files.ghostty.org/libpng-1220aa013f0c83da3fb64ea6d327f9173fa008d10e28bc9349eac3463457723b1c66.tar.gz",
    "hash": "sha256-/syVtGzwXo4/yKQUdQ4LparQDYnp/fF16U/wQcrxoDo="
  },
-  "libxev-0.0.0-86vtc2UaEwDfiTKX3iBI-s_hdzfzWQUarT3MUrmUQl-Q": {
+  "libxev-0.0.0-86vtc4IcEwCqEYxEYoN_3KXmc6A9VLcm22aVImfvecYs": {
    "name": "libxev",
-    "url": "https://github.com/mitchellh/libxev/archive/7f803181b158a10fec8619f793e3b4df515566cb.tar.gz",
-    "hash": "sha256-KaozYKEhhT/6sInef7/8O/60LDBJN+8QmdLuNY1Gkmc="
+    "url": "https://github.com/mitchellh/libxev/archive/34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz",
+    "hash": "sha256-YAPqa5bkpRihKPkyMn15oRvTCZaxO3O66ymRY3lIfdc="
  },
  "N-V-__8AAG3RoQEyRC2Vw7Qoro5SYBf62IHn3HjqtNVY6aWK": {
    "name": "libxml2",
@@ -109,15 +109,20 @@
    "url": "https://deps.files.ghostty.org/utfcpp-1220d4d18426ca72fc2b7e56ce47273149815501d0d2395c2a98c726b31ba931e641.tar.gz",
    "hash": "sha256-/8ZooxDndgfTk/PBizJxXyI9oerExNbgV5oR345rWc8="
  },
-  "uucode-0.1.0-ZZjBPpAFQABNCvd9cVPBg4I7233Ays-NWfWphPNqGbyE": {
+  "uucode-0.1.0-ZZjBPjQHQADuCy1VMWftjrMl3iWqgMpUugWVQJG6_7xT": {
    "name": "uucode",
-    "url": "https://github.com/jacobsandlund/uucode/archive/190706c6b56f0842d29778007f74f7d3d1335fc5.tar.gz",
-    "hash": "sha256-iq9Oyns5e5Tnz2BKPPPTuyJ03BN4bK0dsmSPE1s0wig="
+    "url": "https://github.com/jacobsandlund/uucode/archive/f81f8ef8518b8ec5a7fca30ec5fdbc76cc6197df.tar.gz",
+    "hash": "sha256-VomSYOF8fRJwb/8GtVG/QqR6c95zSkQt4649C/4KXAc="
  },
-  "vaxis-0.1.0-BWNV_FUICQAFZnTCL11TUvnUr1Y0_ZdqtXHhd51d76Rn": {
+  "vaxis-0.5.1-BWNV_H0PCQAeMusmtLzh9P9xO2IW242GZ2IRe9iKYhcA": {
    "name": "vaxis",
-    "url": "git+https://github.com/rockorager/libvaxis#1f41c121e8fc153d9ce8c6eb64b2bbab68ad7d23",
-    "hash": "sha256-bNZ3oveT6vPChjimPJ/GGfcdivlAeJdl/xfWM+S/MHY="
+    "url": "https://github.com/rockorager/libvaxis/archive/1bf887aa7e3736bad69fd4e277a378946edb0f2a.tar.gz",
+    "hash": "sha256-eq5YC26OY0i2cdQJ0ZXMZ+o2vHQLEFNNGzQt5Zuz4BM="
+  },
+  "vaxis-0.5.1-BWNV_O8fCQAeUeVrESVc-2BdXloEXkFqReDJL7Q6XTSZ": {
+    "name": "vaxis",
+    "url": "https://github.com/rockorager/libvaxis/archive/9fc9015d5f147568e18c5e7ca28f15bf8b293760.tar.gz",
+    "hash": "sha256-7H5a0J7uUsrzlO7JNAf/Ussi9WxvmsbyJSmhqvl+rqI="
  },
  "N-V-__8AAKrHGAAs2shYq8UkE6bGcR1QJtLTyOE_lcosMn6t": {
    "name": "wayland",
@@ -134,40 +139,50 @@
    "url": "https://deps.files.ghostty.org/wuffs-122037b39d577ec2db3fd7b2130e7b69ef6cc1807d68607a7c232c958315d381b5cd.tar.gz",
    "hash": "sha256-nkzSCr6W5sTG7enDBXEIhgEm574uLD41UVR2wlC+HBM="
  },
-  "z2d-0.8.1-j5P_Hq8vDwB8ZaDA54-SzESDLF2zznG_zvTHiQNJImZP": {
+  "z2d-0.8.2-pre-j5P_HlVRFgCsBTQ3EgUoKbYHx5JMnyH1mHsOSPiafnef": {
    "name": "z2d",
-    "url": "https://github.com/vancluever/z2d/archive/refs/tags/v0.8.1.tar.gz",
-    "hash": "sha256-0DbDKSYA1ejhVx/WbOkwTgD57PNRFcnRviqBh8xpPZ0="
+    "url": "https://github.com/vancluever/z2d/archive/a1237f6881d99b75abd8a20a934e62e34b44a005.tar.gz",
+    "hash": "sha256-5/qRZAIh1U42v7jql9W0jr2zzQZtu39DxJPLVrSybJg="
  },
-  "zf-0.10.3-OIRy8aiIAACLrBllz0zjxaH0aOe5oNm3KtEMyCntST-9": {
+  "zf-0.10.3-OIRy8QGJAACJcu3tCGtfbJnnd3Y4QL7OW_X8PJ8u_ASR": {
    "name": "zf",
-    "url": "https://github.com/natecraddock/zf/archive/7aacbe6d155d64d15937ca95ca6c014905eb531f.tar.gz",
-    "hash": "sha256-3nulNQd/4rZ4paeXJYXwAliNNyRNsIOX/q3z1JB8C7I="
+    "url": "https://github.com/jcollie/zf/archive/52ad2e5528ab754f77437edf08a07b5ec843661c.tar.gz",
+    "hash": "sha256-8BinbanSfZeBA8SBAopVxwJObN36/BTpxVHABKicsMQ="
  },
-  "zg-0.13.4-AAAAAGiZ7QLz4pvECFa_wG4O4TP4FLABHHbemH2KakWM": {
+  "zg-0.14.1-oGqU3J4_tAKBfyes3AWleKDjo-IcYvnEwaB8qxOqFMwM": {
    "name": "zg",
-    "url": "git+https://codeberg.org/atman/zg#4a002763419a34d61dcbb1f415821b83b9bf8ddc",
-    "hash": "sha256-fo3l6cjkrr/godElTGnQzalBsasN7J73IDIRmw7v1gA="
+    "url": "git+https://codeberg.org/ivanstepanovftw/zg#4fe689e56ce2ed5a8f59308b471bccd7da89fac9",
+    "hash": "sha256-P0ieLuOQ05wKVaMmeNKJIxCWMIdyeKkmhsj8Ps80BGU="
  },
-  "N-V-__8AAB9YCQBaZtQjJZVndk-g_GDIK-NTZcIa63bFp9yZ": {
+  "zg-0.15.1-oGqU3M0-tALZCy7boQS86znlBloyKx6--JriGlY0Paa9": {
+    "name": "zg",
+    "url": "https://codeberg.org/chaten/zg/archive/749197a3f9d25e211615960c02380a3d659b20f9.tar.gz",
+    "hash": "sha256-BZhz1nPqxK6hdsJQ66n7Jk4zMgFSGLXm8eU0CX/7mDI="
+  },
+  "zig_js-0.0.0-rjCAV-6GAADxFug7rDmPH-uM_XcnJ5NmuAMJCAscMjhi": {
    "name": "zig_js",
-    "url": "https://deps.files.ghostty.org/zig_js-12205a66d423259567764fa0fc60c82be35365c21aeb76c5a7dc99698401f4f6fefc.tar.gz",
-    "hash": "sha256-fyNeCVbC9UAaKJY6JhAZlT0A479M/AKYMPIWEZbDWD0="
+    "url": "https://github.com/mitchellh/zig-js/archive/04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz",
+    "hash": "sha256-TCAY5WAV05UEuAkDhq2c6Tk/ODgAhdnDI3O/flb8c6M="
  },
-  "zig_objc-0.0.0-Ir_SpwsPAQBJgi9YRm2ubJMfdoysSq5gKpsIj3izQ8Zk": {
+  "zig_objc-0.0.0-Ir_Sp5gTAQCvxxR7oVIrPXxXwsfKgVP7_wqoOQrZjFeK": {
    "name": "zig_objc",
-    "url": "https://github.com/mitchellh/zig-objc/archive/c9e917a4e15a983b672ca779c7985d738a2d517c.tar.gz",
-    "hash": "sha256-o3vl7qfkSi0bKXa6JWuF92qMEGP8Af/shcip5nRo5Nw="
+    "url": "https://github.com/mitchellh/zig-objc/archive/f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz",
+    "hash": "sha256-3YSvc3YlNW/NciyzCQnzsujXAmZ89XlxSqfqvArAjsw="
  },
-  "wayland-0.4.0-dev-lQa1kjfIAQCmhhQu3xF0KH-94-TzeMXOqfnP0-Dg6Wyy": {
+  "wayland-0.5.0-dev-lQa1khrMAQDJDwYFKpdH3HizherB7sHo5dKMECfvxQHe": {
    "name": "zig_wayland",
-    "url": "https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz",
-    "hash": "sha256-E77GZ15APYbbO1WzmuJi8eG9/iQFbc2CgkNBxjCLUhk="
+    "url": "https://codeberg.org/ifreund/zig-wayland/archive/1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz",
+    "hash": "sha256-TxRrc17Q1Sf1IOO/cdPpP3LD0PpYOujt06SFH3B5Ek4="
  },
-  "zigimg-0.1.0-lly-O6N2EABOxke8dqyzCwhtUCAafqP35zC7wsZ4Ddxj": {
+  "zigimg-0.1.0-8_eo2mWmEgBoqdr0sH9O5GTqDHthkoEPM5_tipcBRreL": {
    "name": "zigimg",
-    "url": "git+https://github.com/TUSF/zigimg#31268548fe3276c0e95f318a6c0d2ab10565b58d",
-    "hash": "sha256-oblfr2FIzuqq0FLo/RrzCwUX1NJJuT53EwD3nP3KwN0="
+    "url": "git+https://github.com/ivanstepanovftw/zigimg#aa4c31db872612c39edbb79f753b3cd9a79fe726",
+    "hash": "sha256-Ko5RuxxTAvpUHCnWEdHqNl7b+PVUAxg1/OPmzGGjdt0="
+  },
+  "zigimg-0.1.0-8_eo2vHnEwCIVW34Q14Ec-xUlzIoVg86-7FU2ypPtxms": {
+    "name": "zigimg",
+    "url": "https://github.com/ivanstepanovftw/zigimg/archive/d7b7ab0ba0899643831ef042bd73289510b39906.tar.gz",
+    "hash": "sha256-LB7Xa6KzVRRUSwwnyWM+y6fDG+kIDjfnoBDJO1obxVM="
  },
  "N-V-__8AAB0eQwD-0MdOEBmz7intriBReIsIDNlukNVoNu6o": {
    "name": "zlib",
--- a/build.zig.zon.nix
+++ b/build.zig.zon.nix
@@ -187,11 +187,11 @@ in
      };
    }
    {
-      name = "libxev-0.0.0-86vtc2UaEwDfiTKX3iBI-s_hdzfzWQUarT3MUrmUQl-Q";
+      name = "libxev-0.0.0-86vtc4IcEwCqEYxEYoN_3KXmc6A9VLcm22aVImfvecYs";
      path = fetchZigArtifact {
        name = "libxev";
-        url = "https://github.com/mitchellh/libxev/archive/7f803181b158a10fec8619f793e3b4df515566cb.tar.gz";
-        hash = "sha256-KaozYKEhhT/6sInef7/8O/60LDBJN+8QmdLuNY1Gkmc=";
+        url = "https://github.com/mitchellh/libxev/archive/34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz";
+        hash = "sha256-YAPqa5bkpRihKPkyMn15oRvTCZaxO3O66ymRY3lIfdc=";
      };
    }
    {
@@ -259,19 +259,27 @@ in
      };
    }
    {
-      name = "uucode-0.1.0-ZZjBPpAFQABNCvd9cVPBg4I7233Ays-NWfWphPNqGbyE";
+      name = "uucode-0.1.0-ZZjBPjQHQADuCy1VMWftjrMl3iWqgMpUugWVQJG6_7xT";
      path = fetchZigArtifact {
        name = "uucode";
-        url = "https://github.com/jacobsandlund/uucode/archive/190706c6b56f0842d29778007f74f7d3d1335fc5.tar.gz";
-        hash = "sha256-iq9Oyns5e5Tnz2BKPPPTuyJ03BN4bK0dsmSPE1s0wig=";
+        url = "https://github.com/jacobsandlund/uucode/archive/f81f8ef8518b8ec5a7fca30ec5fdbc76cc6197df.tar.gz";
+        hash = "sha256-VomSYOF8fRJwb/8GtVG/QqR6c95zSkQt4649C/4KXAc=";
      };
    }
    {
-      name = "vaxis-0.1.0-BWNV_FUICQAFZnTCL11TUvnUr1Y0_ZdqtXHhd51d76Rn";
+      name = "vaxis-0.5.1-BWNV_H0PCQAeMusmtLzh9P9xO2IW242GZ2IRe9iKYhcA";
      path = fetchZigArtifact {
        name = "vaxis";
-        url = "git+https://github.com/rockorager/libvaxis#1f41c121e8fc153d9ce8c6eb64b2bbab68ad7d23";
-        hash = "sha256-bNZ3oveT6vPChjimPJ/GGfcdivlAeJdl/xfWM+S/MHY=";
+        url = "https://github.com/rockorager/libvaxis/archive/1bf887aa7e3736bad69fd4e277a378946edb0f2a.tar.gz";
+        hash = "sha256-eq5YC26OY0i2cdQJ0ZXMZ+o2vHQLEFNNGzQt5Zuz4BM=";
+      };
+    }
+    {
+      name = "vaxis-0.5.1-BWNV_O8fCQAeUeVrESVc-2BdXloEXkFqReDJL7Q6XTSZ";
+      path = fetchZigArtifact {
+        name = "vaxis";
+        url = "https://github.com/rockorager/libvaxis/archive/9fc9015d5f147568e18c5e7ca28f15bf8b293760.tar.gz";
+        hash = "sha256-7H5a0J7uUsrzlO7JNAf/Ussi9WxvmsbyJSmhqvl+rqI=";
      };
    }
    {
@@ -299,59 +307,75 @@ in
      };
    }
    {
-      name = "z2d-0.8.1-j5P_Hq8vDwB8ZaDA54-SzESDLF2zznG_zvTHiQNJImZP";
+      name = "z2d-0.8.2-pre-j5P_HlVRFgCsBTQ3EgUoKbYHx5JMnyH1mHsOSPiafnef";
      path = fetchZigArtifact {
        name = "z2d";
-        url = "https://github.com/vancluever/z2d/archive/refs/tags/v0.8.1.tar.gz";
-        hash = "sha256-0DbDKSYA1ejhVx/WbOkwTgD57PNRFcnRviqBh8xpPZ0=";
+        url = "https://github.com/vancluever/z2d/archive/a1237f6881d99b75abd8a20a934e62e34b44a005.tar.gz";
+        hash = "sha256-5/qRZAIh1U42v7jql9W0jr2zzQZtu39DxJPLVrSybJg=";
      };
    }
    {
-      name = "zf-0.10.3-OIRy8aiIAACLrBllz0zjxaH0aOe5oNm3KtEMyCntST-9";
+      name = "zf-0.10.3-OIRy8QGJAACJcu3tCGtfbJnnd3Y4QL7OW_X8PJ8u_ASR";
      path = fetchZigArtifact {
        name = "zf";
-        url = "https://github.com/natecraddock/zf/archive/7aacbe6d155d64d15937ca95ca6c014905eb531f.tar.gz";
-        hash = "sha256-3nulNQd/4rZ4paeXJYXwAliNNyRNsIOX/q3z1JB8C7I=";
+        url = "https://github.com/jcollie/zf/archive/52ad2e5528ab754f77437edf08a07b5ec843661c.tar.gz";
+        hash = "sha256-8BinbanSfZeBA8SBAopVxwJObN36/BTpxVHABKicsMQ=";
      };
    }
    {
-      name = "zg-0.13.4-AAAAAGiZ7QLz4pvECFa_wG4O4TP4FLABHHbemH2KakWM";
+      name = "zg-0.14.1-oGqU3J4_tAKBfyes3AWleKDjo-IcYvnEwaB8qxOqFMwM";
      path = fetchZigArtifact {
        name = "zg";
-        url = "git+https://codeberg.org/atman/zg#4a002763419a34d61dcbb1f415821b83b9bf8ddc";
-        hash = "sha256-fo3l6cjkrr/godElTGnQzalBsasN7J73IDIRmw7v1gA=";
+        url = "git+https://codeberg.org/ivanstepanovftw/zg#4fe689e56ce2ed5a8f59308b471bccd7da89fac9";
+        hash = "sha256-P0ieLuOQ05wKVaMmeNKJIxCWMIdyeKkmhsj8Ps80BGU=";
      };
    }
    {
-      name = "N-V-__8AAB9YCQBaZtQjJZVndk-g_GDIK-NTZcIa63bFp9yZ";
+      name = "zg-0.15.1-oGqU3M0-tALZCy7boQS86znlBloyKx6--JriGlY0Paa9";
+      path = fetchZigArtifact {
+        name = "zg";
+        url = "https://codeberg.org/chaten/zg/archive/749197a3f9d25e211615960c02380a3d659b20f9.tar.gz";
+        hash = "sha256-BZhz1nPqxK6hdsJQ66n7Jk4zMgFSGLXm8eU0CX/7mDI=";
+      };
+    }
+    {
+      name = "zig_js-0.0.0-rjCAV-6GAADxFug7rDmPH-uM_XcnJ5NmuAMJCAscMjhi";
      path = fetchZigArtifact {
        name = "zig_js";
-        url = "https://deps.files.ghostty.org/zig_js-12205a66d423259567764fa0fc60c82be35365c21aeb76c5a7dc99698401f4f6fefc.tar.gz";
-        hash = "sha256-fyNeCVbC9UAaKJY6JhAZlT0A479M/AKYMPIWEZbDWD0=";
+        url = "https://github.com/mitchellh/zig-js/archive/04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz";
+        hash = "sha256-TCAY5WAV05UEuAkDhq2c6Tk/ODgAhdnDI3O/flb8c6M=";
      };
    }
    {
-      name = "zig_objc-0.0.0-Ir_SpwsPAQBJgi9YRm2ubJMfdoysSq5gKpsIj3izQ8Zk";
+      name = "zig_objc-0.0.0-Ir_Sp5gTAQCvxxR7oVIrPXxXwsfKgVP7_wqoOQrZjFeK";
      path = fetchZigArtifact {
        name = "zig_objc";
-        url = "https://github.com/mitchellh/zig-objc/archive/c9e917a4e15a983b672ca779c7985d738a2d517c.tar.gz";
-        hash = "sha256-o3vl7qfkSi0bKXa6JWuF92qMEGP8Af/shcip5nRo5Nw=";
+        url = "https://github.com/mitchellh/zig-objc/archive/f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz";
+        hash = "sha256-3YSvc3YlNW/NciyzCQnzsujXAmZ89XlxSqfqvArAjsw=";
      };
    }
    {
-      name = "wayland-0.4.0-dev-lQa1kjfIAQCmhhQu3xF0KH-94-TzeMXOqfnP0-Dg6Wyy";
+      name = "wayland-0.5.0-dev-lQa1khrMAQDJDwYFKpdH3HizherB7sHo5dKMECfvxQHe";
      path = fetchZigArtifact {
        name = "zig_wayland";
-        url = "https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz";
-        hash = "sha256-E77GZ15APYbbO1WzmuJi8eG9/iQFbc2CgkNBxjCLUhk=";
+        url = "https://codeberg.org/ifreund/zig-wayland/archive/1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz";
+        hash = "sha256-TxRrc17Q1Sf1IOO/cdPpP3LD0PpYOujt06SFH3B5Ek4=";
      };
    }
    {
-      name = "zigimg-0.1.0-lly-O6N2EABOxke8dqyzCwhtUCAafqP35zC7wsZ4Ddxj";
+      name = "zigimg-0.1.0-8_eo2mWmEgBoqdr0sH9O5GTqDHthkoEPM5_tipcBRreL";
      path = fetchZigArtifact {
        name = "zigimg";
-        url = "git+https://github.com/TUSF/zigimg#31268548fe3276c0e95f318a6c0d2ab10565b58d";
-        hash = "sha256-oblfr2FIzuqq0FLo/RrzCwUX1NJJuT53EwD3nP3KwN0=";
+        url = "git+https://github.com/ivanstepanovftw/zigimg#aa4c31db872612c39edbb79f753b3cd9a79fe726";
+        hash = "sha256-Ko5RuxxTAvpUHCnWEdHqNl7b+PVUAxg1/OPmzGGjdt0=";
+      };
+    }
+    {
+      name = "zigimg-0.1.0-8_eo2vHnEwCIVW34Q14Ec-xUlzIoVg86-7FU2ypPtxms";
+      path = fetchZigArtifact {
+        name = "zigimg";
+        url = "https://github.com/ivanstepanovftw/zigimg/archive/d7b7ab0ba0899643831ef042bd73289510b39906.tar.gz";
+        hash = "sha256-LB7Xa6KzVRRUSwwnyWM+y6fDG+kIDjfnoBDJO1obxVM=";
      };
    }
    {
--- a/build.zig.zon.txt
+++ b/build.zig.zon.txt
@@ -1,7 +1,7 @@
-git+https://codeberg.org/atman/zg#4a002763419a34d61dcbb1f415821b83b9bf8ddc
-git+https://github.com/TUSF/zigimg#31268548fe3276c0e95f318a6c0d2ab10565b58d
-git+https://github.com/rockorager/libvaxis#1f41c121e8fc153d9ce8c6eb64b2bbab68ad7d23
-https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz
+git+https://codeberg.org/ivanstepanovftw/zg#4fe689e56ce2ed5a8f59308b471bccd7da89fac9
+git+https://github.com/ivanstepanovftw/zigimg#aa4c31db872612c39edbb79f753b3cd9a79fe726
+https://codeberg.org/chaten/zg/archive/749197a3f9d25e211615960c02380a3d659b20f9.tar.gz
+https://codeberg.org/ifreund/zig-wayland/archive/1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz
 https://deps.files.ghostty.org/JetBrainsMono-2.304.tar.gz
 https://deps.files.ghostty.org/NerdFontsSymbolsOnly-3.4.0.tar.gz
 https://deps.files.ghostty.org/breakpad-b99f444ba5f6b98cac261cbb391d8766b34a5918.tar.gz
@@ -24,12 +24,15 @@ https://deps.files.ghostty.org/utfcpp-1220d4d18426ca72fc2b7e56ce47273149815501d0
 https://deps.files.ghostty.org/wayland-9cb3d7aa9dc995ffafdbdef7ab86a949d0fb0e7d.tar.gz
 https://deps.files.ghostty.org/wayland-protocols-258d8f88f2c8c25a830c6316f87d23ce1a0f12d9.tar.gz
 https://deps.files.ghostty.org/wuffs-122037b39d577ec2db3fd7b2130e7b69ef6cc1807d68607a7c232c958315d381b5cd.tar.gz
-https://deps.files.ghostty.org/zig_js-12205a66d423259567764fa0fc60c82be35365c21aeb76c5a7dc99698401f4f6fefc.tar.gz
 https://deps.files.ghostty.org/zlib-1220fed0c74e1019b3ee29edae2051788b080cd96e90d56836eea857b0b966742efb.tar.gz
 https://github.com/ghostty-org/zig-gobject/releases/download/2025-09-20-20-1/ghostty-gobject-2025-09-20-20-1.tar.zst
-https://github.com/jacobsandlund/uucode/archive/190706c6b56f0842d29778007f74f7d3d1335fc5.tar.gz
+https://github.com/ivanstepanovftw/zigimg/archive/d7b7ab0ba0899643831ef042bd73289510b39906.tar.gz
+https://github.com/jacobsandlund/uucode/archive/f81f8ef8518b8ec5a7fca30ec5fdbc76cc6197df.tar.gz
+https://github.com/jcollie/zf/archive/52ad2e5528ab754f77437edf08a07b5ec843661c.tar.gz
 https://github.com/mbadolato/iTerm2-Color-Schemes/releases/download/release-20250922-150534-d28055b/ghostty-themes.tgz
-https://github.com/mitchellh/libxev/archive/7f803181b158a10fec8619f793e3b4df515566cb.tar.gz
-https://github.com/mitchellh/zig-objc/archive/c9e917a4e15a983b672ca779c7985d738a2d517c.tar.gz
-https://github.com/natecraddock/zf/archive/7aacbe6d155d64d15937ca95ca6c014905eb531f.tar.gz
-https://github.com/vancluever/z2d/archive/refs/tags/v0.8.1.tar.gz
+https://github.com/mitchellh/libxev/archive/34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz
+https://github.com/mitchellh/zig-js/archive/04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz
+https://github.com/mitchellh/zig-objc/archive/f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz
+https://github.com/rockorager/libvaxis/archive/1bf887aa7e3736bad69fd4e277a378946edb0f2a.tar.gz
+https://github.com/rockorager/libvaxis/archive/9fc9015d5f147568e18c5e7ca28f15bf8b293760.tar.gz
+https://github.com/vancluever/z2d/archive/a1237f6881d99b75abd8a20a934e62e34b44a005.tar.gz
--- a/example/c-vt/build.zig.zon
+++ b/example/c-vt/build.zig.zon
@@ -2,7 +2,7 @@
    .name = .c_vt,
    .version = "0.0.0",
    .fingerprint = 0x413a8529b1255f9a,
-    .minimum_zig_version = "0.14.1",
+    .minimum_zig_version = "0.15.1",
    .dependencies = .{
        // Ghostty dependency. In reality, you'd probably use a URL-based
        // dependency like the one showed (and commented out) below this one.
--- a/example/zig-vt/build.zig.zon
+++ b/example/zig-vt/build.zig.zon
@@ -2,7 +2,7 @@
    .name = .zig_vt,
    .version = "0.0.0",
    .fingerprint = 0x6045575a7a8387e6,
-    .minimum_zig_version = "0.14.1",
+    .minimum_zig_version = "0.15.1",
    .dependencies = .{
        // Ghostty dependency. In reality, you'd probably use a URL-based
        // dependency like the one showed (and commented out) below this one.
--- a/flake.lock
+++ b/flake.lock
@@ -36,15 +36,15 @@
    },
    "nixpkgs": {
      "locked": {
-        "lastModified": 1748189127,
-        "narHash": "sha256-zRDR+EbbeObu4V2X5QCd2Bk5eltfDlCr5yvhBwUT6pY=",
-        "rev": "7c43f080a7f28b2774f3b3f43234ca11661bf334",
+        "lastModified": 315532800,
+        "narHash": "sha256-YwoXN6fthkakCFD7nXPcUK+rkNr6ZTNTuF8zdGaxZo0=",
+        "rev": "dc704e6102e76aad573f63b74c742cd96f8f1e6c",
        "type": "tarball",
-        "url": "https://releases.nixos.org/nixos/25.05/nixos-25.05.802491.7c43f080a7f2/nixexprs.tar.xz"
+        "url": "https://releases.nixos.org/nixpkgs/nixpkgs-25.11pre870318.dc704e6102e7/nixexprs.tar.xz"
      },
      "original": {
        "type": "tarball",
-        "url": "https://channels.nixos.org/nixos-25.05/nixexprs.tar.xz"
+        "url": "https://channels.nixos.org/nixpkgs-unstable/nixexprs.tar.xz"
      }
    },
    "nixpkgs_2": {
@@ -97,11 +97,11 @@
        ]
      },
      "locked": {
-        "lastModified": 1748261582,
-        "narHash": "sha256-3i0IL3s18hdDlbsf0/E+5kyPRkZwGPbSFngq5eToiAA=",
+        "lastModified": 1759192380,
+        "narHash": "sha256-0BWJgt4OSzxCESij5oo8WLWrPZ+1qLp8KUQe32QeV4Q=",
        "owner": "mitchellh",
        "repo": "zig-overlay",
-        "rev": "aafb1b093fb838f7a02613b719e85ec912914221",
+        "rev": "0bcd1401ed43d10f10cbded49624206553e92f57",
        "type": "github"
      },
      "original": {
--- a/flake.nix
+++ b/flake.nix
@@ -5,7 +5,9 @@
    # We want to stay as up to date as possible but need to be careful that the
    # glibc versions used by our dependencies from Nix are compatible with the
    # system glibc that the user is building for.
-    nixpkgs.url = "https://channels.nixos.org/nixos-25.05/nixexprs.tar.xz";
+    #
+    # We are currently on unstable to get Zig 0.15 for our package.nix
+    nixpkgs.url = "https://channels.nixos.org/nixpkgs-unstable/nixexprs.tar.xz";
    flake-utils.url = "github:numtide/flake-utils";

    # Used for shell.nix
@@ -47,7 +49,7 @@
          pkgs = nixpkgs.legacyPackages.${system};
        in {
          devShell.${system} = pkgs.callPackage ./nix/devShell.nix {
-            zig = zig.packages.${system}."0.14.1";
+            zig = zig.packages.${system}."0.15.1";
            wraptest = pkgs.callPackage ./nix/wraptest.nix {};
            zon2nix = zon2nix;
          };
--- a/flatpak/dependencies.yml
+++ b/flatpak/dependencies.yml
@@ -13,12 +13,12 @@ modules:
      - chmod a+x /app/zig/zig
    sources:
      - type: archive
-        sha256: 24aeeec8af16c381934a6cd7d95c807a8cb2cf7df9fa40d359aa884195c4716c
-        url: https://ziglang.org/download/0.14.1/zig-x86_64-linux-0.14.1.tar.xz
+        sha256: c61c5da6edeea14ca51ecd5e4520c6f4189ef5250383db33d01848293bfafe05
+        url: https://ziglang.org/download/0.15.1/zig-x86_64-linux-0.15.1.tar.xz
        only-arches: [x86_64]
      - type: archive
-        sha256: f7a654acc967864f7a050ddacfaa778c7504a0eca8d2b678839c21eea47c992b
-        url: https://ziglang.org/download/0.14.1/zig-aarch64-linux-0.14.1.tar.xz
+        sha256: bb4a8d2ad735e7fba764c497ddf4243cb129fece4148da3222a7046d3f1f19fe
+        url: https://ziglang.org/download/0.15.1/zig-aarch64-linux-0.15.1.tar.xz
        only-arches: [aarch64]

  - name: bzip2-redirect
--- a/flatpak/zig-packages.json
+++ b/flatpak/zig-packages.json
@@ -79,9 +79,9 @@
  },
  {
    "type": "archive",
-    "url": "https://github.com/mitchellh/libxev/archive/7f803181b158a10fec8619f793e3b4df515566cb.tar.gz",
-    "dest": "vendor/p/libxev-0.0.0-86vtc2UaEwDfiTKX3iBI-s_hdzfzWQUarT3MUrmUQl-Q",
-    "sha256": "29aa3360a121853ffab089de7fbffc3bfeb42c304937ef1099d2ee358d469267"
+    "url": "https://github.com/mitchellh/libxev/archive/34fa50878aec6e5fa8f532867001ab3c36fae23e.tar.gz",
+    "dest": "vendor/p/libxev-0.0.0-86vtc4IcEwCqEYxEYoN_3KXmc6A9VLcm22aVImfvecYs",
+    "sha256": "6003ea6b96e4a518a128f932327d79a11bd30996b13b73baeb29916379487dd7"
  },
  {
    "type": "archive",
@@ -133,15 +133,21 @@
  },
  {
    "type": "archive",
-    "url": "https://github.com/jacobsandlund/uucode/archive/190706c6b56f0842d29778007f74f7d3d1335fc5.tar.gz",
-    "dest": "vendor/p/uucode-0.1.0-ZZjBPpAFQABNCvd9cVPBg4I7233Ays-NWfWphPNqGbyE",
-    "sha256": "8aaf4eca7b397b94e7cf604a3cf3d3bb2274dc13786cad1db2648f135b34c228"
+    "url": "https://github.com/jacobsandlund/uucode/archive/f81f8ef8518b8ec5a7fca30ec5fdbc76cc6197df.tar.gz",
+    "dest": "vendor/p/uucode-0.1.0-ZZjBPjQHQADuCy1VMWftjrMl3iWqgMpUugWVQJG6_7xT",
+    "sha256": "56899260e17c7d12706fff06b551bf42a47a73de734a442de3ae3d0bfe0a5c07"
  },
  {
-    "type": "git",
-    "url": "https://github.com/rockorager/libvaxis",
-    "commit": "1f41c121e8fc153d9ce8c6eb64b2bbab68ad7d23",
-    "dest": "vendor/p/vaxis-0.1.0-BWNV_FUICQAFZnTCL11TUvnUr1Y0_ZdqtXHhd51d76Rn"
+    "type": "archive",
+    "url": "https://github.com/rockorager/libvaxis/archive/1bf887aa7e3736bad69fd4e277a378946edb0f2a.tar.gz",
+    "dest": "vendor/p/vaxis-0.5.1-BWNV_H0PCQAeMusmtLzh9P9xO2IW242GZ2IRe9iKYhcA",
+    "sha256": "7aae580b6e8e6348b671d409d195cc67ea36bc740b10534d1b342de59bb3e013"
+  },
+  {
+    "type": "archive",
+    "url": "https://github.com/rockorager/libvaxis/archive/9fc9015d5f147568e18c5e7ca28f15bf8b293760.tar.gz",
+    "dest": "vendor/p/vaxis-0.5.1-BWNV_O8fCQAeUeVrESVc-2BdXloEXkFqReDJL7Q6XTSZ",
+    "sha256": "ec7e5ad09eee52caf394eec93407ff52cb22f56c6f9ac6f22529a1aaf97eaea2"
  },
  {
    "type": "archive",
@@ -163,45 +169,57 @@
  },
  {
    "type": "archive",
-    "url": "https://github.com/vancluever/z2d/archive/refs/tags/v0.8.1.tar.gz",
-    "dest": "vendor/p/z2d-0.8.1-j5P_Hq8vDwB8ZaDA54-SzESDLF2zznG_zvTHiQNJImZP",
-    "sha256": "d036c3292600d5e8e1571fd66ce9304e00f9ecf35115c9d1be2a8187cc693d9d"
+    "url": "https://github.com/vancluever/z2d/archive/a1237f6881d99b75abd8a20a934e62e34b44a005.tar.gz",
+    "dest": "vendor/p/z2d-0.8.2-pre-j5P_HlVRFgCsBTQ3EgUoKbYHx5JMnyH1mHsOSPiafnef",
+    "sha256": "e7fa91640221d54e36bfb8ea97d5b48ebdb3cd066dbb7f43c493cb56b4b26c98"
  },
  {
    "type": "archive",
-    "url": "https://github.com/natecraddock/zf/archive/7aacbe6d155d64d15937ca95ca6c014905eb531f.tar.gz",
-    "dest": "vendor/p/zf-0.10.3-OIRy8aiIAACLrBllz0zjxaH0aOe5oNm3KtEMyCntST-9",
-    "sha256": "de7ba535077fe2b678a5a7972585f002588d37244db08397feadf3d4907c0bb2"
+    "url": "https://github.com/jcollie/zf/archive/52ad2e5528ab754f77437edf08a07b5ec843661c.tar.gz",
+    "dest": "vendor/p/zf-0.10.3-OIRy8QGJAACJcu3tCGtfbJnnd3Y4QL7OW_X8PJ8u_ASR",
+    "sha256": "f018a76da9d27d978103c481028a55c7024e6cddfafc14e9c551c004a89cb0c4"
  },
  {
    "type": "git",
-    "url": "https://codeberg.org/atman/zg",
-    "commit": "4a002763419a34d61dcbb1f415821b83b9bf8ddc",
-    "dest": "vendor/p/zg-0.13.4-AAAAAGiZ7QLz4pvECFa_wG4O4TP4FLABHHbemH2KakWM"
+    "url": "https://codeberg.org/ivanstepanovftw/zg",
+    "commit": "4fe689e56ce2ed5a8f59308b471bccd7da89fac9",
+    "dest": "vendor/p/zg-0.14.1-oGqU3J4_tAKBfyes3AWleKDjo-IcYvnEwaB8qxOqFMwM"
  },
  {
    "type": "archive",
-    "url": "https://deps.files.ghostty.org/zig_js-12205a66d423259567764fa0fc60c82be35365c21aeb76c5a7dc99698401f4f6fefc.tar.gz",
-    "dest": "vendor/p/N-V-__8AAB9YCQBaZtQjJZVndk-g_GDIK-NTZcIa63bFp9yZ",
-    "sha256": "7f235e0956c2f5401a28963a261019953d00e3bf4cfc029830f2161196c3583d"
+    "url": "https://codeberg.org/chaten/zg/archive/749197a3f9d25e211615960c02380a3d659b20f9.tar.gz",
+    "dest": "vendor/p/zg-0.15.1-oGqU3M0-tALZCy7boQS86znlBloyKx6--JriGlY0Paa9",
+    "sha256": "059873d673eac4aea176c250eba9fb264e3332015218b5e6f1e534097ffb9832"
  },
  {
    "type": "archive",
-    "url": "https://github.com/mitchellh/zig-objc/archive/c9e917a4e15a983b672ca779c7985d738a2d517c.tar.gz",
-    "dest": "vendor/p/zig_objc-0.0.0-Ir_SpwsPAQBJgi9YRm2ubJMfdoysSq5gKpsIj3izQ8Zk",
-    "sha256": "a37be5eea7e44a2d1b2976ba256b85f76a8c1063fc01ffec85c8a9e67468e4dc"
+    "url": "https://github.com/mitchellh/zig-js/archive/04db83c617da1956ac5adc1cb9ba1e434c1cb6fd.tar.gz",
+    "dest": "vendor/p/zig_js-0.0.0-rjCAV-6GAADxFug7rDmPH-uM_XcnJ5NmuAMJCAscMjhi",
+    "sha256": "4c2018e56015d39504b8090386ad9ce9393f38380085d9c32373bf7e56fc73a3"
  },
  {
    "type": "archive",
-    "url": "https://codeberg.org/ifreund/zig-wayland/archive/f3c5d503e540ada8cbcb056420de240af0c094f7.tar.gz",
-    "dest": "vendor/p/wayland-0.4.0-dev-lQa1kjfIAQCmhhQu3xF0KH-94-TzeMXOqfnP0-Dg6Wyy",
-    "sha256": "13bec6675e403d86db3b55b39ae262f1e1bdfe24056dcd82824341c6308b5219"
+    "url": "https://github.com/mitchellh/zig-objc/archive/f356ed02833f0f1b8e84d50bed9e807bf7cdc0ae.tar.gz",
+    "dest": "vendor/p/zig_objc-0.0.0-Ir_Sp5gTAQCvxxR7oVIrPXxXwsfKgVP7_wqoOQrZjFeK",
+    "sha256": "dd84af737625356fcd722cb30909f3b2e8d702667cf579714aa7eabc0ac08ecc"
+  },
+  {
+    "type": "archive",
+    "url": "https://codeberg.org/ifreund/zig-wayland/archive/1b5c038ec10da20ed3a15b0b2a6db1c21383e8ea.tar.gz",
+    "dest": "vendor/p/wayland-0.5.0-dev-lQa1khrMAQDJDwYFKpdH3HizherB7sHo5dKMECfvxQHe",
+    "sha256": "4f146b735ed0d527f520e3bf71d3e93f72c3d0fa583ae8edd3a4851f7079124e"
  },
  {
    "type": "git",
-    "url": "https://github.com/TUSF/zigimg",
-    "commit": "31268548fe3276c0e95f318a6c0d2ab10565b58d",
-    "dest": "vendor/p/zigimg-0.1.0-lly-O6N2EABOxke8dqyzCwhtUCAafqP35zC7wsZ4Ddxj"
+    "url": "https://github.com/ivanstepanovftw/zigimg",
+    "commit": "aa4c31db872612c39edbb79f753b3cd9a79fe726",
+    "dest": "vendor/p/zigimg-0.1.0-8_eo2mWmEgBoqdr0sH9O5GTqDHthkoEPM5_tipcBRreL"
+  },
+  {
+    "type": "archive",
+    "url": "https://github.com/ivanstepanovftw/zigimg/archive/d7b7ab0ba0899643831ef042bd73289510b39906.tar.gz",
+    "dest": "vendor/p/zigimg-0.1.0-8_eo2vHnEwCIVW34Q14Ec-xUlzIoVg86-7FU2ypPtxms",
+    "sha256": "2c1ed76ba2b35514544b0c27c9633ecba7c31be9080e37e7a010c93b5a1bc553"
  },
  {
    "type": "archive",
--- a/nix/package.nix
+++ b/nix/package.nix
@@ -10,7 +10,7 @@
  git,
  ncurses,
  pkg-config,
-  zig_0_14,
+  zig_0_15,
  pandoc,
  revision ? "dirty",
  optimize ? "Debug",
@@ -27,7 +27,7 @@
  # https://github.com/ziglang/zig/issues/14281#issuecomment-1624220653 is
  # ultimately acted on and has made its way to a nixpkgs implementation, this
  # can probably be removed in favor of that.
-  zig_hook = zig_0_14.hook.overrideAttrs {
+  zig_hook = zig_0_15.hook.overrideAttrs {
    zig_default_flags = "-Dcpu=baseline -Doptimize=${optimize} --color off";
  };
  gi_typelib_path = import ./build-support/gi-typelib-path.nix {
--- a/pkg/apple-sdk/build.zig
+++ b/pkg/apple-sdk/build.zig
@@ -46,19 +46,19 @@ pub fn addPaths(
        // find the SDK path.
        const libc = try std.zig.LibCInstallation.findNative(.{
            .allocator = b.allocator,
-            .target = step.rootModuleTarget(),
+            .target = &step.rootModuleTarget(),
            .verbose = false,
        });

        // Render the file compatible with the `--libc` Zig flag.
-        var list: std.ArrayList(u8) = .init(b.allocator);
-        defer list.deinit();
-        try libc.render(list.writer());
+        var stream: std.io.Writer.Allocating = .init(b.allocator);
+        defer stream.deinit();
+        try libc.render(&stream.writer);

        // Create a temporary file to store the libc path because
        // `--libc` expects a file path.
        const wf = b.addWriteFiles();
-        const path = wf.add("libc.txt", list.items);
+        const path = wf.add("libc.txt", stream.written());

        // Determine our framework path. Zig has a bug where it doesn't
        // parse this from the libc txt file for `-framework` flags:
--- a/pkg/breakpad/build.zig
+++ b/pkg/breakpad/build.zig
@@ -19,9 +19,8 @@ pub fn build(b: *std.Build) !void {
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{});
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);

    if (b.lazyDependency("breakpad", .{})) |upstream| {
        lib.addIncludePath(upstream.path("src"));
--- a/pkg/cimgui/build.zig
+++ b/pkg/cimgui/build.zig
@@ -55,19 +55,19 @@ pub fn build(b: *std.Build) !void {
    if (imgui_) |imgui| lib.addIncludePath(imgui.path(""));
    module.addIncludePath(b.path("vendor"));

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DCIMGUI_FREETYPE=1",
        "-DIMGUI_USE_WCHAR32=1",
        "-DIMGUI_DISABLE_OBSOLETE_FUNCTIONS=1",
    });
    if (target.result.os.tag == .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DIMGUI_IMPL_API=extern\t\"C\"\t__declspec(dllexport)",
        });
    } else {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DIMGUI_IMPL_API=extern\t\"C\"",
        });
    }
--- a/pkg/fontconfig/build.zig
+++ b/pkg/fontconfig/build.zig
@@ -82,9 +82,9 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    lib.addIncludePath(b.path("override/include"));
    module.addIncludePath(b.path("override/include"));

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DHAVE_DIRENT_H",
        "-DHAVE_FCNTL_H",
        "-DHAVE_STDLIB_H",
@@ -129,12 +129,12 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    });

    switch (target.result.ptrBitWidth()) {
-        32 => try flags.appendSlice(&.{
+        32 => try flags.appendSlice(b.allocator, &.{
            "-DSIZEOF_VOID_P=4",
            "-DALIGNOF_VOID_P=4",
        }),

-        64 => try flags.appendSlice(&.{
+        64 => try flags.appendSlice(b.allocator, &.{
            "-DSIZEOF_VOID_P=8",
            "-DALIGNOF_VOID_P=8",
        }),
@@ -142,14 +142,14 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
        else => @panic("unsupported arch"),
    }
    if (target.result.os.tag == .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DFC_CACHEDIR=\"LOCAL_APPDATA_FONTCONFIG_CACHE\"",
            "-DFC_TEMPLATEDIR=\"c:/share/fontconfig/conf.avail\"",
            "-DCONFIGDIR=\"c:/etc/fonts/conf.d\"",
            "-DFC_DEFAULT_FONTS=\"\\t<dir>WINDOWSFONTDIR</dir>\\n\\t<dir>WINDOWSUSERFONTDIR</dir>\\n\"",
        });
    } else {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DHAVE_FSTATFS",
            "-DHAVE_FSTATVFS",
            "-DHAVE_GETOPT",
@@ -173,13 +173,13 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
        });

        if (target.result.os.tag == .freebsd) {
-            try flags.appendSlice(&.{
+            try flags.appendSlice(b.allocator, &.{
                "-DFC_TEMPLATEDIR=\"/usr/local/etc/fonts/conf.avail\"",
                "-DFONTCONFIG_PATH=\"/usr/local/etc/fonts\"",
                "-DCONFIGDIR=\"/usr/local/etc/fonts/conf.d\"",
            });
        } else {
-            try flags.appendSlice(&.{
+            try flags.appendSlice(b.allocator, &.{
                "-DFC_TEMPLATEDIR=\"/usr/share/fontconfig/conf.avail\"",
                "-DFONTCONFIG_PATH=\"/etc/fonts\"",
                "-DCONFIGDIR=\"/usr/local/fontconfig/conf.d\"",
@@ -187,7 +187,7 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
        }

        if (target.result.os.tag == .linux) {
-            try flags.appendSlice(&.{
+            try flags.appendSlice(b.allocator, &.{
                "-DHAVE_SYS_STATFS_H",
                "-DHAVE_SYS_VFS_H",
            });
@@ -214,14 +214,14 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    // Libxml2
    _ = b.systemIntegrationOption("libxml2", .{}); // So it shows up in help
    if (libxml2_enabled) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DENABLE_LIBXML2",
            "-DLIBXML_STATIC",
            "-DLIBXML_PUSH_ENABLED",
        });
        if (target.result.os.tag == .windows) {
            // NOTE: this should be defined on all targets
-            try flags.appendSlice(&.{
+            try flags.appendSlice(b.allocator, &.{
                "-Werror=implicit-function-declaration",
            });
        }
--- a/pkg/freetype/build.zig
+++ b/pkg/freetype/build.zig
@@ -77,9 +77,9 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DFT2_BUILD_LIBRARY",

        "-DFT_CONFIG_OPTION_SYSTEM_ZLIB=1",
@@ -103,7 +103,7 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    // Libpng
    _ = b.systemIntegrationOption("libpng", .{}); // So it shows up in help
    if (libpng_enabled) {
-        try flags.append("-DFT_CONFIG_OPTION_USE_PNG=1");
+        try flags.append(b.allocator, "-DFT_CONFIG_OPTION_USE_PNG=1");

        if (b.systemIntegrationOption("libpng", .{})) {
            lib.linkSystemLibrary2("libpng", dynamic_link_opts);
--- a/pkg/freetype/face.zig
+++ b/pkg/freetype/face.zig
@@ -193,8 +193,8 @@ pub const Face = struct {
    ) void {
        c.FT_Set_Transform(
            self.handle,
-            @constCast(@ptrCast(matrix)),
-            @constCast(@ptrCast(delta)),
+            @ptrCast(@constCast(matrix)),
+            @ptrCast(@constCast(delta)),
        );
    }
 };
--- a/pkg/glslang/build.zig
+++ b/pkg/glslang/build.zig
@@ -59,9 +59,9 @@ fn buildGlslang(
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-fno-sanitize=undefined",
        "-fno-sanitize-trap=undefined",
    });
--- a/pkg/gtk4-layer-shell/build.zig
+++ b/pkg/gtk4-layer-shell/build.zig
@@ -36,10 +36,13 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    const optimize = options.optimize;

    // Shared library
-    const lib = b.addSharedLibrary(.{
+    const lib = b.addLibrary(.{
        .name = "gtk4-layer-shell",
-        .target = target,
-        .optimize = optimize,
+        .linkage = .dynamic,
+        .root_module = b.createModule(.{
+            .target = target,
+            .optimize = optimize,
+        }),
    });
    b.installArtifact(lib);

--- a/pkg/harfbuzz/build.zig
+++ b/pkg/harfbuzz/build.zig
@@ -111,13 +111,13 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu

    const dynamic_link_opts = options.dynamic_link_opts;

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DHAVE_STDBOOL_H",
    });
    if (target.result.os.tag != .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DHAVE_UNISTD_H",
            "-DHAVE_SYS_MMAN_H",
            "-DHAVE_PTHREAD=1",
@@ -127,7 +127,7 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    // Freetype
    _ = b.systemIntegrationOption("freetype", .{}); // So it shows up in help
    if (freetype_enabled) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DHAVE_FREETYPE=1",

            // Let's just assume a new freetype
@@ -153,7 +153,7 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
    }

    if (coretext_enabled) {
-        try flags.appendSlice(&.{"-DHAVE_CORETEXT=1"});
+        try flags.appendSlice(b.allocator, &.{"-DHAVE_CORETEXT=1"});
        lib.linkFramework("CoreText");
        module.linkFramework("CoreText", .{});
    }
--- a/pkg/highway/build.zig
+++ b/pkg/highway/build.zig
@@ -31,9 +31,9 @@ pub fn build(b: *std.Build) !void {
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        // Avoid changing binaries based on the current time and date.
        "-Wno-builtin-macro-redefined",
        "-D__DATE__=\"redacted\"",
@@ -69,7 +69,7 @@ pub fn build(b: *std.Build) !void {
        "-fno-vectorize",
    });
    if (target.result.os.tag != .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-fmath-errno",
            "-fno-exceptions",
        });
--- a/pkg/libintl/build.zig
+++ b/pkg/libintl/build.zig
@@ -22,9 +22,9 @@ pub fn build(b: *std.Build) !void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DHAVE_CONFIG_H",
        "-DLOCALEDIR=\"\"",
    });
--- a/pkg/libpng/build.zig
+++ b/pkg/libpng/build.zig
@@ -46,9 +46,9 @@ pub fn build(b: *std.Build) !void {
    }

    if (b.lazyDependency("libpng", .{})) |upstream| {
-        var flags = std.ArrayList([]const u8).init(b.allocator);
-        defer flags.deinit();
-        try flags.appendSlice(&.{
+        var flags: std.ArrayList([]const u8) = .empty;
+        defer flags.deinit(b.allocator);
+        try flags.appendSlice(b.allocator, &.{
            "-DPNG_ARM_NEON_OPT=0",
            "-DPNG_POWERPC_VSX_OPT=0",
            "-DPNG_INTEL_SSE_OPT=0",
--- a/pkg/libxml2/build.zig
+++ b/pkg/libxml2/build.zig
@@ -25,9 +25,9 @@ pub fn build(b: *std.Build) !void {
        lib.addIncludePath(b.path("override/config/posix"));
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        // Version info, hardcoded
        comptime "-DLIBXML_VERSION=" ++ Version.number(),
        comptime "-DLIBXML_VERSION_STRING=" ++ Version.string(),
@@ -46,7 +46,7 @@ pub fn build(b: *std.Build) !void {
        "-DWITHOUT_TRIO=1",
    });
    if (target.result.os.tag != .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DHAVE_ARPA_INET_H=1",
            "-DHAVE_ARPA_NAMESER_H=1",
            "-DHAVE_DL_H=1",
@@ -74,25 +74,25 @@ pub fn build(b: *std.Build) !void {
            var nameBuf: [32]u8 = undefined;
            const name = std.ascii.upperString(&nameBuf, field.name);
            const define = try std.fmt.allocPrint(b.allocator, "-DLIBXML_{s}_ENABLED=1", .{name});
-            try flags.append(define);
+            try flags.append(b.allocator, define);

            if (std.mem.eql(u8, field.name, "history")) {
-                try flags.appendSlice(&.{
+                try flags.appendSlice(b.allocator, &.{
                    "-DHAVE_LIBHISTORY=1",
                    "-DHAVE_LIBREADLINE=1",
                });
            }
            if (std.mem.eql(u8, field.name, "mem_debug")) {
-                try flags.append("-DDEBUG_MEMORY_LOCATION=1");
+                try flags.append(b.allocator, "-DDEBUG_MEMORY_LOCATION=1");
            }
            if (std.mem.eql(u8, field.name, "regexp")) {
-                try flags.append("-DLIBXML_UNICODE_ENABLED=1");
+                try flags.append(b.allocator, "-DLIBXML_UNICODE_ENABLED=1");
            }
            if (std.mem.eql(u8, field.name, "run_debug")) {
-                try flags.append("-DLIBXML_DEBUG_RUNTIME=1");
+                try flags.append(b.allocator, "-DLIBXML_DEBUG_RUNTIME=1");
            }
            if (std.mem.eql(u8, field.name, "thread")) {
-                try flags.append("-DHAVE_LIBPTHREAD=1");
+                try flags.append(b.allocator, "-DHAVE_LIBPTHREAD=1");
            }
        }
    }
--- a/pkg/macos/foundation/array.zig
+++ b/pkg/macos/foundation/array.zig
@@ -68,7 +68,7 @@ pub const MutableArray = opaque {
        comptime Elem: type,
        value: *const Elem,
    ) void {
-        CFArrayAppendValue(self, @constCast(@ptrCast(value)));
+        CFArrayAppendValue(self, @ptrCast(@constCast(value)));
    }

    pub fn removeValue(self: *MutableArray, idx: usize) void {
--- a/pkg/macos/foundation/attributed_string.zig
+++ b/pkg/macos/foundation/attributed_string.zig
@@ -10,7 +10,7 @@ pub const AttributedString = opaque {
        str: *foundation.String,
        attributes: *foundation.Dictionary,
    ) Allocator.Error!*AttributedString {
-        return @constCast(@ptrCast(c.CFAttributedStringCreate(
+        return @ptrCast(@constCast(c.CFAttributedStringCreate(
            null,
            @ptrCast(str),
            @ptrCast(attributes),
--- a/pkg/macos/foundation/dictionary.zig
+++ b/pkg/macos/foundation/dictionary.zig
@@ -17,8 +17,8 @@ pub const Dictionary = opaque {

        return @as(?*Dictionary, @ptrFromInt(@intFromPtr(c.CFDictionaryCreate(
            null,
-            @constCast(@ptrCast(if (keys) |slice| slice.ptr else null)),
-            @constCast(@ptrCast(if (values) |slice| slice.ptr else null)),
+            @ptrCast(@constCast(if (keys) |slice| slice.ptr else null)),
+            @ptrCast(@constCast(if (values) |slice| slice.ptr else null)),
            @intCast(if (keys) |slice| slice.len else 0),
            &c.kCFTypeDictionaryKeyCallBacks,
            &c.kCFTypeDictionaryValueCallBacks,
--- a/pkg/macos/os/log.zig
+++ b/pkg/macos/os/log.zig
@@ -32,10 +32,11 @@ pub const Log = opaque {
        comptime format: []const u8,
        args: anytype,
    ) void {
-        const str = nosuspend std.fmt.allocPrintZ(
+        const str = nosuspend std.fmt.allocPrintSentinel(
            alloc,
            format,
            args,
+            0,
        ) catch return;
        defer alloc.free(str);
        zig_os_log_with_type(self, typ, str.ptr);
--- a/pkg/macos/text/font.zig
+++ b/pkg/macos/text/font.zig
@@ -68,7 +68,7 @@ pub const Font = opaque {
    }

    pub fn copyTable(self: *Font, tag: FontTableTag) ?*foundation.Data {
-        return @constCast(@ptrCast(c.CTFontCopyTable(
+        return @ptrCast(@constCast(c.CTFontCopyTable(
            @ptrCast(self),
            @intFromEnum(tag),
            c.kCTFontTableOptionNoOptions,
@@ -90,7 +90,7 @@ pub const Font = opaque {
    }

    pub fn createPathForGlyph(self: *Font, glyph: graphics.Glyph) ?*graphics.Path {
-        return @constCast(@ptrCast(c.CTFontCreatePathForGlyph(
+        return @ptrCast(@constCast(c.CTFontCreatePathForGlyph(
            @ptrCast(self),
            glyph,
            null,
--- a/pkg/macos/text/line.zig
+++ b/pkg/macos/text/line.zig
@@ -51,7 +51,7 @@ pub const Line = opaque {
    }

    pub fn getGlyphRuns(self: *Line) *foundation.Array {
-        return @constCast(@ptrCast(c.CTLineGetGlyphRuns(@ptrCast(self))));
+        return @ptrCast(@constCast(c.CTLineGetGlyphRuns(@ptrCast(self))));
    }
 };

--- a/pkg/macos/video/display_link.zig
+++ b/pkg/macos/video/display_link.zig
@@ -74,7 +74,7 @@ pub const DisplayLink = opaque {

                    callbackFn(
                        displayLink,
-                        @alignCast(@ptrCast(inner_userinfo)),
+                        @ptrCast(@alignCast(inner_userinfo)),
                    );
                    return c.kCVReturnSuccess;
                }
--- a/pkg/oniguruma/build.zig
+++ b/pkg/oniguruma/build.zig
@@ -100,9 +100,8 @@ fn buildLib(b: *std.Build, module: *std.Build.Module, options: anytype) !*std.Bu
            .SIZEOF_VOIDP = t.ptrBitWidth() / t.cTypeBitSize(.char),
        }));

-        var flags = std.ArrayList([]const u8).init(b.allocator);
-        defer flags.deinit();
-        try flags.appendSlice(&.{});
+        var flags: std.ArrayList([]const u8) = .empty;
+        defer flags.deinit(b.allocator);
        lib.addCSourceFiles(.{
            .root = upstream.path(""),
            .flags = flags.items,
--- a/pkg/oniguruma/init.zig
+++ b/pkg/oniguruma/init.zig
@@ -6,7 +6,7 @@ const errors = @import("errors.zig");
 /// the encodings that the program will use.
 pub fn init(encs: []const *Encoding) !void {
    _ = try errors.convertError(c.onig_initialize(
-        @constCast(@ptrCast(@alignCast(encs.ptr))),
+        @ptrCast(@alignCast(@constCast(encs.ptr))),
        @intCast(encs.len),
    ));
 }
--- a/pkg/sentry/build.zig
+++ b/pkg/sentry/build.zig
@@ -26,22 +26,21 @@ pub fn build(b: *std.Build) !void {
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{});
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
    if (target.result.os.tag == .windows) {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DSENTRY_WITH_UNWINDER_DBGHELP",
        });
    } else {
-        try flags.appendSlice(&.{
+        try flags.appendSlice(b.allocator, &.{
            "-DSENTRY_WITH_UNWINDER_LIBBACKTRACE",
        });
    }
    switch (backend) {
-        .crashpad => try flags.append("-DSENTRY_BACKEND_CRASHPAD"),
-        .breakpad => try flags.append("-DSENTRY_BACKEND_BREAKPAD"),
-        .inproc => try flags.append("-DSENTRY_BACKEND_INPROC"),
+        .crashpad => try flags.append(b.allocator, "-DSENTRY_BACKEND_CRASHPAD"),
+        .breakpad => try flags.append(b.allocator, "-DSENTRY_BACKEND_BREAKPAD"),
+        .inproc => try flags.append(b.allocator, "-DSENTRY_BACKEND_INPROC"),
        .none => {},
    }

--- a/pkg/simdutf/build.zig
+++ b/pkg/simdutf/build.zig
@@ -20,11 +20,11 @@ pub fn build(b: *std.Build) !void {
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
    // Zig 0.13 bug: https://github.com/ziglang/zig/issues/20414
    // (See root Ghostty build.zig on why we do this)
-    try flags.appendSlice(&.{"-DSIMDUTF_IMPLEMENTATION_ICELAKE=0"});
+    try flags.appendSlice(b.allocator, &.{"-DSIMDUTF_IMPLEMENTATION_ICELAKE=0"});

    lib.addCSourceFiles(.{
        .flags = flags.items,
--- a/pkg/spirv-cross/build.zig
+++ b/pkg/spirv-cross/build.zig
@@ -64,9 +64,9 @@ fn buildSpirvCross(
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.appendSlice(b.allocator, &.{
        "-DSPIRV_CROSS_C_API_GLSL=1",
        "-DSPIRV_CROSS_C_API_MSL=1",

--- a/pkg/utfcpp/build.zig
+++ b/pkg/utfcpp/build.zig
@@ -19,9 +19,8 @@ pub fn build(b: *std.Build) !void {
        try apple_sdk.addPaths(b, lib);
    }

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.appendSlice(&.{});
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);

    lib.addCSourceFiles(.{
        .flags = flags.items,
--- a/pkg/wuffs/build.zig
+++ b/pkg/wuffs/build.zig
@@ -17,11 +17,11 @@ pub fn build(b: *std.Build) !void {
    });
    unit_tests.linkLibC();

-    var flags = std.ArrayList([]const u8).init(b.allocator);
-    defer flags.deinit();
-    try flags.append("-DWUFFS_IMPLEMENTATION");
+    var flags: std.ArrayList([]const u8) = .empty;
+    defer flags.deinit(b.allocator);
+    try flags.append(b.allocator, "-DWUFFS_IMPLEMENTATION");
    inline for (@import("src/c.zig").defines) |key| {
-        try flags.append("-D" ++ key);
+        try flags.append(b.allocator, "-D" ++ key);
    }

    if (b.lazyDependency("wuffs", .{})) |wuffs_dep| {
--- a/pkg/wuffs/src/jpeg.zig
+++ b/pkg/wuffs/src/jpeg.zig
@@ -31,7 +31,7 @@ pub fn decode(alloc: Allocator, data: []const u8) Error!ImageData {
    }

    var source_buffer: c.wuffs_base__io_buffer = .{
-        .data = .{ .ptr = @constCast(@ptrCast(data.ptr)), .len = data.len },
+        .data = .{ .ptr = @ptrCast(@constCast(data.ptr)), .len = data.len },
        .meta = .{
            .wi = data.len,
            .ri = 0,
--- a/pkg/wuffs/src/png.zig
+++ b/pkg/wuffs/src/png.zig
@@ -31,7 +31,7 @@ pub fn decode(alloc: Allocator, data: []const u8) Error!ImageData {
    }

    var source_buffer: c.wuffs_base__io_buffer = .{
-        .data = .{ .ptr = @constCast(@ptrCast(data.ptr)), .len = data.len },
+        .data = .{ .ptr = @ptrCast(@constCast(data.ptr)), .len = data.len },
        .meta = .{
            .wi = data.len,
            .ri = 0,
--- a/pkg/zlib/build.zig
+++ b/pkg/zlib/build.zig
@@ -26,9 +26,9 @@ pub fn build(b: *std.Build) !void {
            .{ .include_extensions = &.{".h"} },
        );

-        var flags = std.ArrayList([]const u8).init(b.allocator);
-        defer flags.deinit();
-        try flags.appendSlice(&.{
+        var flags: std.ArrayList([]const u8) = .empty;
+        defer flags.deinit(b.allocator);
+        try flags.appendSlice(b.allocator, &.{
            "-DHAVE_SYS_TYPES_H",
            "-DHAVE_STDINT_H",
            "-DHAVE_STDDEF_H",
--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@@ -52,7 +52,7 @@ parts:
      rm -rf $CRAFT_PART_SRC/*

      if [[ -n $arch ]]; then
-        curl -LO --retry-connrefused --retry 10 https://ziglang.org/download/0.14.0/zig-linux-$arch-0.14.0.tar.xz
+        curl -LO --retry-connrefused --retry 10 https://ziglang.org/download/0.15.1/zig-$arch-linux-0.15.1.tar.xz
      else
        echo "Unsupported arch"
        exit 1
--- a/src/Command.zig
+++ b/src/Command.zig
@@ -194,7 +194,9 @@ fn startPosix(self: *Command, arena: Allocator) !void {
    // child process so there isn't much we can do. We try to output
    // something reasonable. Its important to note we MUST NOT return
    // any other error condition from here on out.
-    const stderr = std.io.getStdErr().writer();
+    var stderr_buf: [1024]u8 = undefined;
+    var stderr_writer = std.fs.File.stderr().writer(&stderr_buf);
+    const stderr = &stderr_writer.interface;
    switch (err) {
        error.FileNotFound => stderr.print(
            \\Requested executable not found. Please verify the command is on
@@ -211,6 +213,7 @@ fn startPosix(self: *Command, arena: Allocator) !void {
            .{err},
        ) catch {},
    }
+    stderr.flush() catch {};

    // We return a very specific error that can be detected to determine
    // we're in the child.
@@ -464,34 +467,35 @@ fn createWindowsEnvBlock(allocator: mem.Allocator, env_map: *const EnvMap) ![]u1

 /// Copied from Zig. This function could be made public in child_process.zig instead.
 fn windowsCreateCommandLine(allocator: mem.Allocator, argv: []const []const u8) ![:0]u8 {
-    var buf = std.ArrayList(u8).init(allocator);
+    var buf: std.Io.Writer.Allocating = .init(allocator);
    defer buf.deinit();
+    const writer = &buf.writer;

    for (argv, 0..) |arg, arg_i| {
-        if (arg_i != 0) try buf.append(' ');
+        if (arg_i != 0) try writer.writeByte(' ');
        if (mem.indexOfAny(u8, arg, " \t\n\"") == null) {
-            try buf.appendSlice(arg);
+            try writer.writeAll(arg);
            continue;
        }
-        try buf.append('"');
+        try writer.writeByte('"');
        var backslash_count: usize = 0;
        for (arg) |byte| {
            switch (byte) {
                '\\' => backslash_count += 1,
                '"' => {
-                    try buf.appendNTimes('\\', backslash_count * 2 + 1);
-                    try buf.append('"');
+                    try writer.splatByteAll('\\', backslash_count * 2 + 1);
+                    try writer.writeByte('"');
                    backslash_count = 0;
                },
                else => {
-                    try buf.appendNTimes('\\', backslash_count);
-                    try buf.append(byte);
+                    try writer.splatByteAll('\\', backslash_count);
+                    try writer.writeByte(byte);
                    backslash_count = 0;
                },
            }
        }
-        try buf.appendNTimes('\\', backslash_count * 2);
-        try buf.append('"');
+        try writer.splatByteAll('\\', backslash_count * 2);
+        try writer.writeByte('"');
    }

    return buf.toOwnedSliceSentinel(0);
--- a/src/Surface.zig
+++ b/src/Surface.zig
@@ -305,19 +305,19 @@ const DerivedConfig = struct {

        // Build all of our links
        const links = links: {
-            var links = std.ArrayList(Link).init(alloc);
-            defer links.deinit();
+            var links: std.ArrayList(Link) = .empty;
+            defer links.deinit(alloc);
            for (config.link.links.items) |link| {
                var regex = try link.oniRegex();
                errdefer regex.deinit();
-                try links.append(.{
+                try links.append(alloc, .{
                    .regex = regex,
                    .action = link.action,
                    .highlight = link.highlight,
                });
            }

-            break :links try links.toOwnedSlice();
+            break :links try links.toOwnedSlice(alloc);
        };
        errdefer {
            for (links) |*link| link.regex.deinit();
@@ -1009,7 +1009,7 @@ pub fn handleMessage(self: *Surface, msg: Message) !void {
            self.command_timer = null;

            const duration: Duration = .{ .duration = end.since(start) };
-            log.debug("command took {}", .{duration});
+            log.debug("command took {f}", .{duration});

            _ = self.rt_app.performAction(
                .{ .surface = self },
@@ -2493,7 +2493,7 @@ fn maybeHandleBinding(
    self.keyboard.bindings = null;

    // Attempt to perform the action
-    log.debug("key event binding flags={} action={}", .{
+    log.debug("key event binding flags={} action={f}", .{
        leaf.flags,
        action,
    });
@@ -5119,7 +5119,9 @@ fn writeScreenFile(
    defer file.close();

    // Screen.dumpString writes byte-by-byte, so buffer it
-    var buf_writer = std.io.bufferedWriter(file.writer());
+    var buf: [4096]u8 = undefined;
+    var file_writer = file.writer(&buf);
+    var buf_writer = &file_writer.interface;

    // Write the scrollback contents. This requires a lock.
    {
@@ -5169,7 +5171,7 @@ fn writeScreenFile(
        const br = sel.bottomRight(&self.io.terminal.screen);

        try self.io.terminal.screen.dumpString(
-            buf_writer.writer(),
+            buf_writer,
            .{
                .tl = tl,
                .br = br,
--- a/src/apprt/action.zig
+++ b/src/apprt/action.zig
@@ -578,7 +578,7 @@ pub const SetTitle = struct {
        value: @This(),
        comptime _: []const u8,
        _: std.fmt.FormatOptions,
-        writer: anytype,
+        writer: *std.Io.Writer,
    ) !void {
        try writer.print("{s}{{ {s} }}", .{ @typeName(@This()), value.title });
    }
@@ -602,7 +602,7 @@ pub const Pwd = struct {
        value: @This(),
        comptime _: []const u8,
        _: std.fmt.FormatOptions,
-        writer: anytype,
+        writer: *std.Io.Writer,
    ) !void {
        try writer.print("{s}{{ {s} }}", .{ @typeName(@This()), value.pwd });
    }
@@ -630,7 +630,7 @@ pub const DesktopNotification = struct {
        value: @This(),
        comptime _: []const u8,
        _: std.fmt.FormatOptions,
-        writer: anytype,
+        writer: *std.Io.Writer,
    ) !void {
        try writer.print("{s}{{ title: {s}, body: {s} }}", .{
            @typeName(@This()),
--- a/src/apprt/embedded.zig
+++ b/src/apprt/embedded.zig
@@ -266,8 +266,8 @@ pub const App = struct {
        // embedded apprt.
        self.performPreAction(target, action, value);

-        log.debug("dispatching action target={s} action={} value={}", .{
-            @tagName(target),
+        log.debug("dispatching action target={t} action={} value={any}", .{
+            target,
            action,
            value,
        });
@@ -1910,7 +1910,7 @@ pub const CAPI = struct {
        };

        return ptr.core_surface.performBindingAction(action) catch |err| {
-            log.err("error performing binding action action={} err={}", .{ action, err });
+            log.err("error performing binding action action={f} err={}", .{ action, err });
            return false;
        };
    }
--- a/src/apprt/gtk/adw_version.zig
+++ b/src/apprt/gtk/adw_version.zig
@@ -27,7 +27,7 @@ pub fn getRuntimeVersion() std.SemanticVersion {
 }

 pub fn logVersion() void {
-    log.info("libadwaita version build={} runtime={}", .{
+    log.info("libadwaita version build={f} runtime={f}", .{
        comptime_version,
        getRuntimeVersion(),
    });
--- a/src/apprt/gtk/build/blueprint.zig
+++ b/src/apprt/gtk/build/blueprint.zig
@@ -45,7 +45,7 @@ pub fn main() !void {
        std.debug.print(
            \\`libadwaita` is too old.
            \\
-            \\Ghostty requires a version {} or newer of `libadwaita` to
+            \\Ghostty requires a version {f} or newer of `libadwaita` to
            \\compile this blueprint. Please install it, ensure that it is
            \\available on your PATH, and then retry building Ghostty.
        , .{required_adwaita_version});
@@ -80,7 +80,7 @@ pub fn main() !void {
                std.debug.print(
                    \\`blueprint-compiler` not found.
                    \\
-                    \\Ghostty requires version {} or newer of
+                    \\Ghostty requires version {f} or newer of
                    \\`blueprint-compiler` as a build-time dependency starting
                    \\from version 1.2. Please install it, ensure that it is
                    \\available on your PATH, and then retry building Ghostty.
@@ -104,7 +104,7 @@ pub fn main() !void {
            std.debug.print(
                \\`blueprint-compiler` is the wrong version.
                \\
-                \\Ghostty requires version {} or newer of
+                \\Ghostty requires version {f} or newer of
                \\`blueprint-compiler` as a build-time dependency starting
                \\from version 1.2. Please install it, ensure that it is
                \\available on your PATH, and then retry building Ghostty.
@@ -145,7 +145,7 @@ pub fn main() !void {
                std.debug.print(
                    \\`blueprint-compiler` not found.
                    \\
-                    \\Ghostty requires version {} or newer of
+                    \\Ghostty requires version {f} or newer of
                    \\`blueprint-compiler` as a build-time dependency starting
                    \\from version 1.2. Please install it, ensure that it is
                    \\available on your PATH, and then retry building Ghostty.
--- a/src/apprt/gtk/build/gresource.zig
+++ b/src/apprt/gtk/build/gresource.zig
@@ -142,7 +142,9 @@ pub fn main() !void {
        );
    }

-    const writer = std.io.getStdOut().writer();
+    var buf: [4096]u8 = undefined;
+    var stdout = std.fs.File.stdout().writer(&buf);
+    const writer = &stdout.interface;
    try writer.writeAll(
        \\<?xml version="1.0" encoding="UTF-8"?>
        \\<gresources>
@@ -157,12 +159,14 @@ pub fn main() !void {
        \\</gresources>
        \\
    );
+
+    try stdout.end();
 }

 /// Generate the icon resources. This works by looking up all the icons
 /// specified by `icon_sizes` in `images/icons/`. They are asserted to exist
 /// by trying to access the file.
-fn genIcons(writer: anytype) !void {
+fn genIcons(writer: *std.Io.Writer) !void {
    try writer.print(
        \\  <gresource prefix="{s}/icons">
        \\
@@ -204,7 +208,7 @@ fn genIcons(writer: anytype) !void {
 }

 /// Generate the resources at the root prefix.
-fn genRoot(writer: anytype) !void {
+fn genRoot(writer: *std.Io.Writer) !void {
    try writer.print(
        \\  <gresource prefix="{s}">
        \\
@@ -236,7 +240,7 @@ fn genRoot(writer: anytype) !void {
 /// assuming these will be
 fn genUi(
    alloc: Allocator,
-    writer: anytype,
+    writer: *std.Io.Writer,
    files: *const std.ArrayListUnmanaged([]const u8),
 ) !void {
    try writer.print(
--- a/src/apprt/gtk/cgroup.zig
+++ b/src/apprt/gtk/cgroup.zig
@@ -50,7 +50,7 @@ pub fn init(
        ) orelse "";
        if (!std.mem.eql(u8, original, current)) break :transient current;
        alloc.free(current);
-        std.time.sleep(25 * std.time.ns_per_ms);
+        std.Thread.sleep(25 * std.time.ns_per_ms);
    };
    errdefer alloc.free(transient);
    log.info("transient scope created cgroup={s}", .{transient});
@@ -101,21 +101,21 @@ fn enableControllers(alloc: Allocator, cgroup: []const u8) !void {
    defer alloc.free(raw);

    // Build our string builder for enabling all controllers
-    var builder = std.ArrayList(u8).init(alloc);
+    var builder: std.Io.Writer.Allocating = .init(alloc);
    defer builder.deinit();

    // Controllers are space-separated
    var it = std.mem.splitScalar(u8, raw, ' ');
    while (it.next()) |controller| {
-        try builder.append('+');
-        try builder.appendSlice(controller);
-        if (it.rest().len > 0) try builder.append(' ');
+        try builder.writer.writeByte('+');
+        try builder.writer.writeAll(controller);
+        if (it.rest().len > 0) try builder.writer.writeByte(' ');
    }

    // Enable them all
    try internal_os.cgroup.configureControllers(
        cgroup,
-        builder.items,
+        builder.written(),
    );
 }

--- a/src/apprt/gtk/class.zig
+++ b/src/apprt/gtk/class.zig
@@ -282,7 +282,7 @@ pub fn Common(
                fn setter(self: *Self, value: ?[:0]const u8) void {
                    const priv = private(self);
                    if (@field(priv, name)) |v| {
-                        glib.free(@constCast(@ptrCast(v)));
+                        glib.free(@ptrCast(@constCast(v)));
                    }

                    // We don't need to copy this because it was already
--- a/src/apprt/gtk/class/application.zig
+++ b/src/apprt/gtk/class/application.zig
@@ -1044,7 +1044,9 @@ pub const Application = extern struct {
            defer file.close();

            log.info("loading gtk-custom-css path={s}", .{path});
-            const contents = try file.reader().readAllAlloc(
+            var buf: [4096]u8 = undefined;
+            var reader = file.reader(&buf);
+            const contents = try reader.interface.readAlloc(
                alloc,
                5 * 1024 * 1024, // 5MB,
            );
@@ -1115,8 +1117,8 @@ pub const Application = extern struct {
            // This should really never, never happen. Its not critical enough
            // to actually crash, but this is a bug somewhere. An accelerator
            // for a trigger can't possibly be more than 1024 bytes.
-            error.NoSpaceLeft => {
-                log.warn("accelerator somehow longer than 1024 bytes: {}", .{trigger});
+            error.WriteFailed => {
+                log.warn("accelerator somehow longer than 1024 bytes: {f}", .{trigger});
                return;
            },
        };
--- a/src/apprt/gtk/class/command_palette.zig
+++ b/src/apprt/gtk/class/command_palette.zig
@@ -485,10 +485,11 @@ const Command = extern struct {

        const command = priv.command orelse return null;

-        priv.action_key = std.fmt.allocPrintZ(
+        priv.action_key = std.fmt.allocPrintSentinel(
            priv.arena.allocator(),
-            "{}",
+            "{f}",
            .{command.action},
+            0,
        ) catch null;

        return priv.action_key;
--- a/src/apprt/gtk/class/config.zig
+++ b/src/apprt/gtk/class/config.zig
@@ -117,10 +117,10 @@ pub const Config = extern struct {
        errdefer text_buf.unref();

        var buf: [4095:0]u8 = undefined;
-        var fbs = std.io.fixedBufferStream(&buf);
+        var writer: std.Io.Writer = .fixed(&buf);
        for (config._diagnostics.items()) |diag| {
-            fbs.reset();
-            diag.write(fbs.writer()) catch |err| {
+            writer.end = 0;
+            diag.format(&writer) catch |err| {
                log.warn(
                    "error writing diagnostic to buffer err={}",
                    .{err},
@@ -128,7 +128,7 @@ pub const Config = extern struct {
                continue;
            };

-            text_buf.insertAtCursor(&buf, @intCast(fbs.pos));
+            text_buf.insertAtCursor(&buf, @intCast(writer.end));
            text_buf.insertAtCursor("\n", 1);
        }

--- a/src/apprt/gtk/class/global_shortcuts.zig
+++ b/src/apprt/gtk/class/global_shortcuts.zig
@@ -188,9 +188,9 @@ pub const GlobalShortcuts = extern struct {
                // If there isn't space to translate the trigger, then our
                // buffer might be too small (but 1024 is insane!). In any case
                // we don't want to stop registering globals.
-                error.NoSpaceLeft => {
+                error.WriteFailed => {
                    log.warn(
-                        "buffer too small to translate trigger, ignoring={}",
+                        "buffer too small to translate trigger, ignoring={f}",
                        .{entry.key_ptr.*},
                    );
                    continue;
@@ -257,7 +257,7 @@ pub const GlobalShortcuts = extern struct {
                        const trigger = entry.key_ptr.*.ptr;
                        const action = std.fmt.bufPrintZ(
                            &action_buf,
-                            "{}",
+                            "{f}",
                            .{entry.value_ptr.*},
                        ) catch continue;

--- a/src/apprt/gtk/class/resize_overlay.zig
+++ b/src/apprt/gtk/class/resize_overlay.zig
@@ -172,7 +172,7 @@ pub const ResizeOverlay = extern struct {
    /// overlay if it is currently hidden; you must call schedule.
    pub fn setLabel(self: *Self, label: ?[:0]const u8) void {
        const priv = self.private();
-        if (priv.label_text) |v| glib.free(@constCast(@ptrCast(v)));
+        if (priv.label_text) |v| glib.free(@ptrCast(@constCast(v)));
        priv.label_text = null;
        if (label) |v| priv.label_text = glib.ext.dupeZ(u8, v);
        self.as(gobject.Object).notifyByPspec(properties.label.impl.param_spec);
@@ -285,7 +285,7 @@ pub const ResizeOverlay = extern struct {
    fn finalize(self: *Self) callconv(.c) void {
        const priv = self.private();
        if (priv.label_text) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.label_text = null;
        }

--- a/src/apprt/gtk/class/split_tree.zig
+++ b/src/apprt/gtk/class/split_tree.zig
@@ -268,7 +268,7 @@ pub const SplitTree = extern struct {
        );
        defer new_tree.deinit();
        log.debug(
-            "new split at={} direction={} old_tree={} new_tree={}",
+            "new split at={} direction={} old_tree={f} new_tree={f}",
            .{ handle, direction, old_tree, &new_tree },
        );

--- a/src/apprt/gtk/class/surface.zig
+++ b/src/apprt/gtk/class/surface.zig
@@ -1375,11 +1375,11 @@ pub const Surface = extern struct {
        defer arena.deinit();
        const alloc = arena.allocator();

-        var env_to_remove = std.ArrayList([]const u8).init(alloc);
-        var env_to_update = std.ArrayList(struct {
+        var env_to_remove: std.ArrayList([]const u8) = .empty;
+        var env_to_update: std.ArrayList(struct {
            key: []const u8,
            value: []const u8,
-        }).init(alloc);
+        }) = .empty;

        var it = env_map.iterator();
        while (it.next()) |entry| {
@@ -1392,13 +1392,11 @@ pub const Surface = extern struct {

            // Any env var starting with SNAP must be removed
            if (std.mem.startsWith(u8, key, "SNAP_")) {
-                try env_to_remove.append(key);
+                try env_to_remove.append(alloc, key);
                continue;
            }

-            var filtered_paths = std.ArrayList([]const u8).init(alloc);
-            defer filtered_paths.deinit();
-
+            var filtered_paths: std.ArrayList([]const u8) = .empty;
            var modified = false;
            var paths = std.mem.splitAny(u8, value, ":");
            while (paths.next()) |path| {
@@ -1411,15 +1409,15 @@ pub const Surface = extern struct {
                        break;
                    }
                };
-                if (include) try filtered_paths.append(path);
+                if (include) try filtered_paths.append(alloc, path);
            }

            if (modified) {
                if (filtered_paths.items.len > 0) {
                    const new_value = try std.mem.join(alloc, ":", filtered_paths.items);
-                    try env_to_update.append(.{ .key = key, .value = new_value });
+                    try env_to_update.append(alloc, .{ .key = key, .value = new_value });
                } else {
-                    try env_to_remove.append(key);
+                    try env_to_remove.append(alloc, key);
                }
            }
        }
@@ -1626,7 +1624,7 @@ pub const Surface = extern struct {
            priv.core_surface = null;
        }
        if (priv.mouse_hover_url) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.mouse_hover_url = null;
        }
        if (priv.default_size) |v| {
@@ -1642,15 +1640,15 @@ pub const Surface = extern struct {
            priv.min_size = null;
        }
        if (priv.pwd) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.pwd = null;
        }
        if (priv.title) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.title = null;
        }
        if (priv.title_override) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.title_override = null;
        }
        self.clearCgroup();
@@ -1674,7 +1672,7 @@ pub const Surface = extern struct {
    /// title. For manually set titles see `setTitleOverride`.
    pub fn setTitle(self: *Self, title: ?[:0]const u8) void {
        const priv = self.private();
-        if (priv.title) |v| glib.free(@constCast(@ptrCast(v)));
+        if (priv.title) |v| glib.free(@ptrCast(@constCast(v)));
        priv.title = null;
        if (title) |v| priv.title = glib.ext.dupeZ(u8, v);
        self.as(gobject.Object).notifyByPspec(properties.title.impl.param_spec);
@@ -1684,7 +1682,7 @@ pub const Surface = extern struct {
    /// unless this is unset (null).
    pub fn setTitleOverride(self: *Self, title: ?[:0]const u8) void {
        const priv = self.private();
-        if (priv.title_override) |v| glib.free(@constCast(@ptrCast(v)));
+        if (priv.title_override) |v| glib.free(@ptrCast(@constCast(v)));
        priv.title_override = null;
        if (title) |v| priv.title_override = glib.ext.dupeZ(u8, v);
        self.as(gobject.Object).notifyByPspec(properties.@"title-override".impl.param_spec);
@@ -1698,7 +1696,7 @@ pub const Surface = extern struct {
    /// Set the pwd for this surface, copies the value.
    pub fn setPwd(self: *Self, pwd: ?[:0]const u8) void {
        const priv = self.private();
-        if (priv.pwd) |v| glib.free(@constCast(@ptrCast(v)));
+        if (priv.pwd) |v| glib.free(@ptrCast(@constCast(v)));
        priv.pwd = null;
        if (pwd) |v| priv.pwd = glib.ext.dupeZ(u8, v);
        self.as(gobject.Object).notifyByPspec(properties.pwd.impl.param_spec);
@@ -1783,7 +1781,7 @@ pub const Surface = extern struct {

    pub fn setMouseHoverUrl(self: *Self, url: ?[:0]const u8) void {
        const priv = self.private();
-        if (priv.mouse_hover_url) |v| glib.free(@constCast(@ptrCast(v)));
+        if (priv.mouse_hover_url) |v| glib.free(@ptrCast(@constCast(v)));
        priv.mouse_hover_url = null;
        if (url) |v| priv.mouse_hover_url = glib.ext.dupeZ(u8, v);
        self.as(gobject.Object).notifyByPspec(properties.@"mouse-hover-url".impl.param_spec);
@@ -2117,13 +2115,11 @@ pub const Surface = extern struct {
        const alloc = Application.default().allocator();

        if (ext.gValueHolds(value, gdk.FileList.getGObjectType())) {
-            var data = std.ArrayList(u8).init(alloc);
-            defer data.deinit();
+            var stream: std.Io.Writer.Allocating = .init(alloc);
+            defer stream.deinit();

-            var shell_escape_writer: internal_os.ShellEscapeWriter(std.ArrayList(u8).Writer) = .{
-                .child_writer = data.writer(),
-            };
-            const writer = shell_escape_writer.writer();
+            var shell_escape_writer: internal_os.ShellEscapeWriter = .init(&stream.writer);
+            const writer = &shell_escape_writer.writer;

            const list: ?*glib.SList = list: {
                const unboxed = value.getBoxed() orelse return 0;
@@ -2151,7 +2147,7 @@ pub const Surface = extern struct {
                }
            }

-            const string = data.toOwnedSliceSentinel(0) catch |err| {
+            const string = stream.toOwnedSliceSentinel(0) catch |err| {
                log.err("unable to convert to a slice: {}", .{err});
                return 0;
            };
@@ -2164,13 +2160,11 @@ pub const Surface = extern struct {
            const object = value.getObject() orelse return 0;
            const file = gobject.ext.cast(gio.File, object) orelse return 0;
            const path = file.getPath() orelse return 0;
-            var data = std.ArrayList(u8).init(alloc);
-            defer data.deinit();
+            var stream: std.Io.Writer.Allocating = .init(alloc);
+            defer stream.deinit();

-            var shell_escape_writer: internal_os.ShellEscapeWriter(std.ArrayList(u8).Writer) = .{
-                .child_writer = data.writer(),
-            };
-            const writer = shell_escape_writer.writer();
+            var shell_escape_writer: internal_os.ShellEscapeWriter = .init(&stream.writer);
+            const writer = &shell_escape_writer.writer;
            writer.writeAll(std.mem.span(path)) catch |err| {
                log.err("unable to write path to buffer: {}", .{err});
                return 0;
@@ -2180,7 +2174,7 @@ pub const Surface = extern struct {
                return 0;
            };

-            const string = data.toOwnedSliceSentinel(0) catch |err| {
+            const string = stream.toOwnedSliceSentinel(0) catch |err| {
                log.err("unable to convert to a slice: {}", .{err});
                return 0;
            };
--- a/src/apprt/gtk/class/surface_title_dialog.zig
+++ b/src/apprt/gtk/class/surface_title_dialog.zig
@@ -136,7 +136,7 @@ pub const SurfaceTitleDialog = extern struct {
    fn finalize(self: *Self) callconv(.c) void {
        const priv = self.private();
        if (priv.initial_value) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.initial_value = null;
        }

--- a/src/apprt/gtk/class/tab.zig
+++ b/src/apprt/gtk/class/tab.zig
@@ -270,11 +270,11 @@ pub const Tab = extern struct {
    fn finalize(self: *Self) callconv(.c) void {
        const priv = self.private();
        if (priv.tooltip) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.tooltip = null;
        }
        if (priv.title) |v| {
-            glib.free(@constCast(@ptrCast(v)));
+            glib.free(@ptrCast(@constCast(v)));
            priv.title = null;
        }

@@ -405,22 +405,21 @@ pub const Tab = extern struct {
        };

        // Use an allocator to build up our string as we write it.
-        var buf: std.ArrayList(u8) = .init(Application.default().allocator());
+        var buf: std.Io.Writer.Allocating = .init(Application.default().allocator());
        defer buf.deinit();
-        const writer = buf.writer();

        // If our bell is ringing, then we prefix the bell icon to the title.
        if (bell_ringing and config.@"bell-features".title) {
-            writer.writeAll("🔔 ") catch {};
+            buf.writer.writeAll("🔔 ") catch {};
        }

        // If we're zoomed, prefix with the magnifying glass emoji.
        if (zoomed) {
-            writer.writeAll("🔍 ") catch {};
+            buf.writer.writeAll("🔍 ") catch {};
        }

-        writer.writeAll(plain) catch return glib.ext.dupeZ(u8, plain);
-        return glib.ext.dupeZ(u8, buf.items);
+        buf.writer.writeAll(plain) catch return glib.ext.dupeZ(u8, plain);
+        return glib.ext.dupeZ(u8, buf.written());
    }

    const C = Common(Self, Private);
--- a/src/apprt/gtk/gtk_version.zig
+++ b/src/apprt/gtk/gtk_version.zig
@@ -26,7 +26,7 @@ pub fn getRuntimeVersion() std.SemanticVersion {
 }

 pub fn logVersion() void {
-    log.info("GTK version build={} runtime={}", .{
+    log.info("GTK version build={f} runtime={f}", .{
        comptime_version,
        getRuntimeVersion(),
    });
--- a/src/apprt/gtk/ipc/DBus.zig
+++ b/src/apprt/gtk/ipc/DBus.zig
@@ -29,7 +29,10 @@ payload_builder: *glib.VariantBuilder,
 parameters_builder: *glib.VariantBuilder,

 /// Initialize the helper.
-pub fn init(alloc: Allocator, target: apprt.ipc.Target, action: [:0]const u8) (Allocator.Error || std.posix.WriteError || apprt.ipc.Errors)!Self {
+pub fn init(alloc: Allocator, target: apprt.ipc.Target, action: [:0]const u8) (Allocator.Error || std.Io.Writer.Error || apprt.ipc.Errors)!Self {
+    var buf: [256]u8 = undefined;
+    var stderr_writer = std.fs.File.stderr().writer(&buf);
+    const stderr = &stderr_writer.interface;

    // Get the appropriate bus name and object path for contacting the
    // Ghostty instance we're interested in.
@@ -37,7 +40,7 @@ pub fn init(alloc: Allocator, target: apprt.ipc.Target, action: [:0]const u8) (A
        .class => |class| result: {
            // Force the usage of the class specified on the CLI to determine the
            // bus name and object path.
-            const object_path = try std.fmt.allocPrintZ(alloc, "/{s}", .{class});
+            const object_path = try std.fmt.allocPrintSentinel(alloc, "/{s}", .{class}, 0);

            std.mem.replaceScalar(u8, object_path, '.', '/');
            std.mem.replaceScalar(u8, object_path, '-', '_');
@@ -54,14 +57,14 @@ pub fn init(alloc: Allocator, target: apprt.ipc.Target, action: [:0]const u8) (A
    }

    if (gio.Application.idIsValid(bus_name.ptr) == 0) {
-        const stderr = std.io.getStdErr().writer();
        try stderr.print("D-Bus bus name is not valid: {s}\n", .{bus_name});
+        try stderr.flush();
        return error.IPCFailed;
    }

    if (glib.Variant.isObjectPath(object_path.ptr) == 0) {
-        const stderr = std.io.getStdErr().writer();
        try stderr.print("D-Bus object path is not valid: {s}\n", .{object_path});
+        try stderr.flush();
        return error.IPCFailed;
    }

@@ -72,17 +75,17 @@ pub fn init(alloc: Allocator, target: apprt.ipc.Target, action: [:0]const u8) (A

        const dbus_ = gio.busGetSync(.session, null, &err_);
        if (err_) |err| {
-            const stderr = std.io.getStdErr().writer();
            try stderr.print(
                "Unable to establish connection to D-Bus session bus: {s}\n",
                .{err.f_message orelse "(unknown)"},
            );
+            try stderr.flush();
            return error.IPCFailed;
        }

        break :dbus dbus_ orelse {
-            const stderr = std.io.getStdErr().writer();
            try stderr.print("gio.busGetSync returned null\n", .{});
+            try stderr.flush();
            return error.IPCFailed;
        };
    };
@@ -128,7 +131,11 @@ pub fn addParameter(self: *Self, variant: *glib.Variant) void {

 /// Send the IPC to the remote Ghostty. Once it completes, nothing further
 /// should be done with this object other than call `deinit`.
-pub fn send(self: *Self) (std.posix.WriteError || apprt.ipc.Errors)!void {
+pub fn send(self: *Self) (std.Io.Writer.Error || apprt.ipc.Errors)!void {
+    var buf: [256]u8 = undefined;
+    var stderr_writer = std.fs.File.stderr().writer(&buf);
+    const stderr = &stderr_writer.interface;
+
    // finish building the parameters
    const parameters = self.parameters_builder.end();

@@ -167,11 +174,11 @@ pub fn send(self: *Self) (std.posix.WriteError || apprt.ipc.Errors)!void {
        defer if (result_) |result| result.unref();

        if (err_) |err| {
-            const stderr = std.io.getStdErr().writer();
            try stderr.print(
                "D-Bus method call returned an error err={s}\n",
                .{err.f_message orelse "(unknown)"},
            );
+            try stderr.flush();
            return error.IPCFailed;
        }
    }
--- a/src/apprt/gtk/ipc/new_window.zig
+++ b/src/apprt/gtk/ipc/new_window.zig
@@ -20,7 +20,7 @@ const DBus = @import("DBus.zig");
 // ```
 // gdbus call --session --dest com.mitchellh.ghostty --object-path /com/mitchellh/ghostty --method org.gtk.Actions.Activate new-window-command '[<@as ["echo" "hello"]>]' []
 // ```
-pub fn newWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ipc.Action.NewWindow) (Allocator.Error || std.posix.WriteError || apprt.ipc.Errors)!bool {
+pub fn newWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ipc.Action.NewWindow) (Allocator.Error || std.Io.Writer.Error || apprt.ipc.Errors)!bool {
    var dbus = try DBus.init(
        alloc,
        target,
--- a/src/apprt/gtk/key.zig
+++ b/src/apprt/gtk/key.zig
@@ -12,9 +12,8 @@ const winproto = @import("winproto.zig");
 pub fn accelFromTrigger(
    buf: []u8,
    trigger: input.Binding.Trigger,
-) error{NoSpaceLeft}!?[:0]const u8 {
-    var buf_stream = std.io.fixedBufferStream(buf);
-    const writer = buf_stream.writer();
+) error{WriteFailed}!?[:0]const u8 {
+    var writer: std.Io.Writer = .fixed(buf);

    // Modifiers
    if (trigger.mods.shift) try writer.writeAll("<Shift>");
@@ -23,11 +22,11 @@ pub fn accelFromTrigger(
    if (trigger.mods.super) try writer.writeAll("<Super>");

    // Write our key
-    if (!try writeTriggerKey(writer, trigger)) return null;
+    if (!try writeTriggerKey(&writer, trigger)) return null;

    // We need to make the string null terminated.
    try writer.writeByte(0);
-    const slice = buf_stream.getWritten();
+    const slice = writer.buffered();
    return slice[0 .. slice.len - 1 :0];
 }

@@ -36,9 +35,8 @@ pub fn accelFromTrigger(
 pub fn xdgShortcutFromTrigger(
    buf: []u8,
    trigger: input.Binding.Trigger,
-) error{NoSpaceLeft}!?[:0]const u8 {
-    var buf_stream = std.io.fixedBufferStream(buf);
-    const writer = buf_stream.writer();
+) error{WriteFailed}!?[:0]const u8 {
+    var writer: std.Io.Writer = .fixed(buf);

    // Modifiers
    if (trigger.mods.shift) try writer.writeAll("SHIFT+");
@@ -52,15 +50,18 @@ pub fn xdgShortcutFromTrigger(
    // to *X11's* keysyms (which I assume is a subset of libxkbcommon's).
    // I haven't been able to any evidence to back up that assumption but
    // this works for now
-    if (!try writeTriggerKey(writer, trigger)) return null;
+    if (!try writeTriggerKey(&writer, trigger)) return null;

    // We need to make the string null terminated.
    try writer.writeByte(0);
-    const slice = buf_stream.getWritten();
+    const slice = writer.buffered();
    return slice[0 .. slice.len - 1 :0];
 }

-fn writeTriggerKey(writer: anytype, trigger: input.Binding.Trigger) error{NoSpaceLeft}!bool {
+fn writeTriggerKey(
+    writer: *std.Io.Writer,
+    trigger: input.Binding.Trigger,
+) error{WriteFailed}!bool {
    switch (trigger.key) {
        .physical => |k| {
            const keyval = keyvalFromKey(k) orelse return false;
--- a/src/benchmark/CodepointWidth.zig
+++ b/src/benchmark/CodepointWidth.zig
@@ -10,7 +10,6 @@ const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const Benchmark = @import("Benchmark.zig");
 const options = @import("options.zig");
-const uucode = @import("uucode");
 const UTF8Decoder = @import("../terminal/UTF8Decoder.zig");
 const simd = @import("../simd/main.zig");
 const table = @import("../unicode/main.zig").table;
@@ -48,9 +47,6 @@ pub const Mode = enum {

    /// Test our lookup table implementation.
    table,
-
-    /// Using uucode, with custom `width` extension based on `wcwidth`.
-    uucode,
 };

 /// Create a new terminal stream handler for the given arguments.
@@ -75,7 +71,6 @@ pub fn benchmark(self: *CodepointWidth) Benchmark {
            .wcwidth => stepWcwidth,
            .table => stepTable,
            .simd => stepSimd,
-            .uucode => stepUucode,
        },
        .setupFn = setup,
        .teardownFn = teardown,
@@ -112,12 +107,15 @@ fn stepWcwidth(ptr: *anyopaque) Benchmark.Error!void {
    const self: *CodepointWidth = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;
+
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
@@ -136,12 +134,15 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
    const self: *CodepointWidth = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;
+
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
@@ -165,12 +166,15 @@ fn stepSimd(ptr: *anyopaque) Benchmark.Error!void {
    const self: *CodepointWidth = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;
+
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
@@ -185,35 +189,6 @@ fn stepSimd(ptr: *anyopaque) Benchmark.Error!void {
    }
 }

-fn stepUucode(ptr: *anyopaque) Benchmark.Error!void {
-    const self: *CodepointWidth = @ptrCast(@alignCast(ptr));
-
-    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
-    var d: UTF8Decoder = .{};
-    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
-    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
-            return error.BenchmarkFailed;
-        };
-        if (n == 0) break; // EOF reached
-
-        for (buf[0..n]) |c| {
-            const cp_, const consumed = d.next(c);
-            assert(consumed);
-            if (cp_) |cp| {
-                // This is the same trick we do in terminal.zig so we
-                // keep it here.
-                std.mem.doNotOptimizeAway(if (cp <= 0xFF)
-                    1
-                else
-                    uucode.get(.width, @intCast(cp)));
-            }
-        }
-    }
-}
-
 test CodepointWidth {
    const testing = std.testing;
    const alloc = testing.allocator;
--- a/src/benchmark/GraphemeBreak.zig
+++ b/src/benchmark/GraphemeBreak.zig
@@ -8,7 +8,6 @@ const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const Benchmark = @import("Benchmark.zig");
 const options = @import("options.zig");
-const uucode = @import("uucode");
 const UTF8Decoder = @import("../terminal/UTF8Decoder.zig");
 const unicode = @import("../unicode/main.zig");

@@ -39,9 +38,6 @@ pub const Mode = enum {

    /// Ghostty's table-based approach.
    table,
-
-    /// uucode implementation
-    uucode,
 };

 /// Create a new terminal stream handler for the given arguments.
@@ -64,7 +60,6 @@ pub fn benchmark(self: *GraphemeBreak) Benchmark {
        .stepFn = switch (self.opts.mode) {
            .noop => stepNoop,
            .table => stepTable,
-            .uucode => stepUucode,
        },
        .setupFn = setup,
        .teardownFn = teardown,
@@ -95,12 +90,15 @@ fn stepNoop(ptr: *anyopaque) Benchmark.Error!void {
    const self: *GraphemeBreak = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;
+
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
@@ -115,14 +113,17 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
    const self: *GraphemeBreak = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;
+
    var d: UTF8Decoder = .{};
    var state: unicode.GraphemeBreakState = .{};
    var cp1: u21 = 0;
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
@@ -138,33 +139,6 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
    }
 }

-fn stepUucode(ptr: *anyopaque) Benchmark.Error!void {
-    const self: *GraphemeBreak = @ptrCast(@alignCast(ptr));
-
-    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
-    var d: UTF8Decoder = .{};
-    var state: uucode.grapheme.BreakState = .default;
-    var cp1: u21 = 0;
-    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
-    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
-            return error.BenchmarkFailed;
-        };
-        if (n == 0) break; // EOF reached
-
-        for (buf[0..n]) |c| {
-            const cp_, const consumed = d.next(c);
-            assert(consumed);
-            if (cp_) |cp2| {
-                std.mem.doNotOptimizeAway(uucode.grapheme.isBreak(cp1, @intCast(cp2), &state));
-                cp1 = cp2;
-            }
-        }
-    }
-}
-
 test GraphemeBreak {
    const testing = std.testing;
    const alloc = testing.allocator;
--- a/src/benchmark/IsSymbol.zig
+++ b/src/benchmark/IsSymbol.zig
@@ -90,7 +90,8 @@ fn stepUucode(ptr: *anyopaque) Benchmark.Error!void {
    const self: *IsSymbol = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var r = f.reader(&read_buf);
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
@@ -114,7 +115,8 @@ fn stepTable(ptr: *anyopaque) Benchmark.Error!void {
    const self: *IsSymbol = @ptrCast(@alignCast(ptr));

    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var r = f.reader(&read_buf);
    var d: UTF8Decoder = .{};
    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
    while (true) {
--- a/src/benchmark/TerminalParser.zig
+++ b/src/benchmark/TerminalParser.zig
@@ -75,14 +75,16 @@ fn step(ptr: *anyopaque) Benchmark.Error!void {
    // the benchmark results and... I know writing this that we
    // aren't currently IO bound.
    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    var r = &f_reader.interface;

    var p: terminalpkg.Parser = .init();

-    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
+    var buf: [4096]u8 = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
--- a/src/benchmark/TerminalStream.zig
+++ b/src/benchmark/TerminalStream.zig
@@ -113,17 +113,19 @@ fn step(ptr: *anyopaque) Benchmark.Error!void {
    // the benchmark results and... I know writing this that we
    // aren't currently IO bound.
    const f = self.data_f orelse return;
-    var r = std.io.bufferedReader(f.reader());

-    var buf: [4096]u8 align(std.atomic.cache_line) = undefined;
+    var read_buf: [4096]u8 = undefined;
+    var f_reader = f.reader(&read_buf);
+    const r = &f_reader.interface;
+
+    var buf: [4096]u8 = undefined;
    while (true) {
-        const n = r.read(&buf) catch |err| {
-            log.warn("error reading data file err={}", .{err});
+        const n = r.readSliceShort(&buf) catch {
+            log.warn("error reading data file err={?}", .{f_reader.err});
            return error.BenchmarkFailed;
        };
        if (n == 0) break; // EOF reached
-        const chunk = buf[0..n];
-        self.stream.nextSlice(chunk) catch |err| {
+        self.stream.nextSlice(buf[0..n]) catch |err| {
            log.warn("error processing data file chunk err={}", .{err});
            return error.BenchmarkFailed;
        };
--- a/src/benchmark/options.zig
+++ b/src/benchmark/options.zig
@@ -10,7 +10,7 @@ pub fn dataFile(path_: ?[]const u8) !?std.fs.File {
    const path = path_ orelse return null;

    // Stdin
-    if (std.mem.eql(u8, path, "-")) return std.io.getStdIn();
+    if (std.mem.eql(u8, path, "-")) return .stdin();

    // Normal file
    const file = try std.fs.cwd().openFile(path, .{});
--- a/src/build/Config.zig
+++ b/src/build/Config.zig
@@ -477,7 +477,7 @@ pub fn addOptions(self: *const Config, step: *std.Build.Step.Options) !void {
    step.addOption(std.SemanticVersion, "app_version", self.version);
    step.addOption([:0]const u8, "app_version_string", try std.fmt.bufPrintZ(
        &buf,
-        "{}",
+        "{f}",
        .{self.version},
    ));
    step.addOption(
--- a/src/build/GhosttyBench.zig
+++ b/src/build/GhosttyBench.zig
@@ -11,8 +11,8 @@ pub fn init(
    b: *std.Build,
    deps: *const SharedDeps,
 ) !GhosttyBench {
-    var steps = std.ArrayList(*std.Build.Step.Compile).init(b.allocator);
-    errdefer steps.deinit();
+    var steps: std.ArrayList(*std.Build.Step.Compile) = .empty;
+    errdefer steps.deinit(b.allocator);

    // Our synthetic data generator
    {
@@ -28,7 +28,7 @@ pub fn init(
        });
        exe.linkLibC();
        _ = try deps.add(exe);
-        try steps.append(exe);
+        try steps.append(b.allocator, exe);
    }

    // Our benchmarking application.
@@ -44,7 +44,7 @@ pub fn init(
        });
        exe.linkLibC();
        _ = try deps.add(exe);
-        try steps.append(exe);
+        try steps.append(b.allocator, exe);
    }

    return .{ .steps = steps.items };
--- a/src/build/GhosttyDist.zig
+++ b/src/build/GhosttyDist.zig
@@ -43,10 +43,10 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyDist {

    // embed the Ghostty version in the tarball
    {
-        const version = b.addWriteFiles().add("VERSION", b.fmt("{}", .{cfg.version}));
+        const version = b.addWriteFiles().add("VERSION", b.fmt("{f}", .{cfg.version}));
        // --add-file uses the most recent --prefix to determine the path
        // in the archive to copy the file (the directory only).
-        git_archive.addArg(b.fmt("--prefix=ghostty-{}/", .{
+        git_archive.addArg(b.fmt("--prefix=ghostty-{f}/", .{
            cfg.version,
        }));
        git_archive.addPrefixedFileArg("--add-file=", version);
@@ -65,7 +65,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyDist {

        // --add-file uses the most recent --prefix to determine the path
        // in the archive to copy the file (the directory only).
-        git_archive.addArg(b.fmt("--prefix=ghostty-{}/{s}/", .{
+        git_archive.addArg(b.fmt("--prefix=ghostty-{f}/{s}/", .{
            cfg.version,
            std.fs.path.dirname(resource.dist).?,
        }));
@@ -77,11 +77,11 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyDist {
        // This is important. Standard source tarballs extract into
        // a directory named `project-version`. This is expected by
        // standard tooling such as debhelper and rpmbuild.
-        b.fmt("--prefix=ghostty-{}/", .{cfg.version}),
+        b.fmt("--prefix=ghostty-{f}/", .{cfg.version}),
        "-o",
    });
    const output = git_archive.addOutputFileArg(b.fmt(
-        "ghostty-{}.tar.gz",
+        "ghostty-{f}.tar.gz",
        .{cfg.version},
    ));
    git_archive.addArg("HEAD");
@@ -89,7 +89,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyDist {
    // The install step to put the dist into the build directory.
    const install = b.addInstallFile(
        output,
-        b.fmt("dist/ghostty-{}.tar.gz", .{cfg.version}),
+        b.fmt("dist/ghostty-{f}.tar.gz", .{cfg.version}),
    );

    // The check step to ensure the archive works.
@@ -101,7 +101,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyDist {
    // i.e. this is way `build.zig` is.
    const extract_dir = check
        .addOutputDirectoryArg("ghostty")
-        .path(b, b.fmt("ghostty-{}", .{cfg.version}));
+        .path(b, b.fmt("ghostty-{f}", .{cfg.version}));

    // Check that tests pass within the extracted directory. This isn't
    // a fully hermetic test because we're sharing the Zig cache. In
--- a/src/build/GhosttyDocs.zig
+++ b/src/build/GhosttyDocs.zig
@@ -12,8 +12,8 @@ pub fn init(
    b: *std.Build,
    deps: *const SharedDeps,
 ) !GhosttyDocs {
-    var steps = std.ArrayList(*std.Build.Step).init(b.allocator);
-    errdefer steps.deinit();
+    var steps: std.ArrayList(*std.Build.Step) = .empty;
+    errdefer steps.deinit(b.allocator);

    const manpages = [_]struct {
        name: []const u8,
@@ -52,7 +52,7 @@ pub fn init(
        const generate_markdown_step = b.addRunArtifact(generate_markdown);
        const markdown_output = generate_markdown_step.captureStdOut();

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            markdown_output,
            "share/ghostty/doc/" ++ manpage.name ++ "." ++ manpage.section ++ ".md",
        ).step);
@@ -67,7 +67,7 @@ pub fn init(
        });
        generate_html.addFileArg(markdown_output);

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            generate_html.captureStdOut(),
            "share/ghostty/doc/" ++ manpage.name ++ "." ++ manpage.section ++ ".html",
        ).step);
@@ -82,7 +82,7 @@ pub fn init(
        });
        generate_manpage.addFileArg(markdown_output);

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            generate_manpage.captureStdOut(),
            "share/man/man" ++ manpage.section ++ "/" ++ manpage.name ++ "." ++ manpage.section,
        ).step);
--- a/src/build/GhosttyExe.zig
+++ b/src/build/GhosttyExe.zig
@@ -21,6 +21,8 @@ pub fn init(b: *std.Build, cfg: *const Config, deps: *const SharedDeps) !Ghostty
            .omit_frame_pointer = cfg.strip,
            .unwind_tables = if (cfg.strip) .none else .sync,
        }),
+        // Crashes on x86_64 self-hosted on 0.15.1
+        .use_llvm = true,
    });
    const install_step = b.addInstallArtifact(exe, .{});

--- a/src/build/GhosttyFrameData.zig
+++ b/src/build/GhosttyFrameData.zig
@@ -40,7 +40,10 @@ pub fn distResources(b: *std.Build) struct {
 } {
    const exe = b.addExecutable(.{
        .name = "framegen",
-        .target = b.graph.host,
+        .root_module = b.createModule(.{
+            .target = b.graph.host,
+        }),
+        .use_llvm = true,
    });
    exe.addCSourceFile(.{
        .file = b.path("src/build/framegen/main.c"),
--- a/src/build/GhosttyI18n.zig
+++ b/src/build/GhosttyI18n.zig
@@ -18,8 +18,8 @@ update_step: *std.Build.Step,
 pub fn init(b: *std.Build, cfg: *const Config) !GhosttyI18n {
    _ = cfg;

-    var steps = std.ArrayList(*std.Build.Step).init(b.allocator);
-    defer steps.deinit();
+    var steps: std.ArrayList(*std.Build.Step) = .empty;
+    defer steps.deinit(b.allocator);

    inline for (locales) |locale| {
        // There is no encoding suffix in the LC_MESSAGES path on FreeBSD,
@@ -33,7 +33,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyI18n {
        const msgfmt = b.addSystemCommand(&.{ "msgfmt", "-o", "-" });
        msgfmt.addFileArg(b.path("po/" ++ locale ++ ".po"));

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            msgfmt.captureStdOut(),
            std.fmt.comptimePrint(
                "share/locale/{s}/LC_MESSAGES/{s}.mo",
@@ -45,7 +45,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyI18n {
    return .{
        .owner = b,
        .update_step = try createUpdateStep(b),
-        .steps = try steps.toOwnedSlice(),
+        .steps = try steps.toOwnedSlice(b.allocator),
    };
 }

--- a/src/build/GhosttyLib.zig
+++ b/src/build/GhosttyLib.zig
@@ -28,7 +28,9 @@ pub fn initStatic(
            .omit_frame_pointer = deps.config.strip,
            .unwind_tables = if (deps.config.strip) .none else .sync,
        }),
-        .linkage = .static,
+
+        // Fails on self-hosted x86_64 on macOS
+        .use_llvm = true,
    });
    lib.linkLibC();

@@ -40,7 +42,7 @@ pub fn initStatic(
    // Add our dependencies. Get the list of all static deps so we can
    // build a combined archive if necessary.
    var lib_list = try deps.add(lib);
-    try lib_list.append(lib.getEmittedBin());
+    try lib_list.append(b.allocator, lib.getEmittedBin());

    if (!deps.config.target.result.os.tag.isDarwin()) return .{
        .step = &lib.step,
@@ -69,8 +71,9 @@ pub fn initShared(
    b: *std.Build,
    deps: *const SharedDeps,
 ) !GhosttyLib {
-    const lib = b.addSharedLibrary(.{
+    const lib = b.addLibrary(.{
        .name = "ghostty",
+        .linkage = .dynamic,
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main_c.zig"),
            .target = deps.config.target,
@@ -79,6 +82,9 @@ pub fn initShared(
            .omit_frame_pointer = deps.config.strip,
            .unwind_tables = if (deps.config.strip) .none else .sync,
        }),
+
+        // Fails on self-hosted x86_64
+        .use_llvm = true,
    });
    _ = try deps.add(lib);

--- a/src/build/GhosttyLibVt.zig
+++ b/src/build/GhosttyLibVt.zig
@@ -24,8 +24,9 @@ pub fn initShared(
    zig: *const GhosttyZig,
 ) !GhosttyLibVt {
    const target = zig.vt.resolved_target.?;
-    const lib = b.addSharedLibrary(.{
+    const lib = b.addLibrary(.{
        .name = "ghostty-vt",
+        .linkage = .dynamic,
        .root_module = zig.vt_c,
        .version = std.SemanticVersion{ .major = 0, .minor = 1, .patch = 0 },
    });
--- a/src/build/GhosttyResources.zig
+++ b/src/build/GhosttyResources.zig
@@ -10,8 +10,8 @@ const RunStep = std.Build.Step.Run;
 steps: []*std.Build.Step,

 pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
-    var steps = std.ArrayList(*std.Build.Step).init(b.allocator);
-    errdefer steps.deinit();
+    var steps: std.ArrayList(*std.Build.Step) = .empty;
+    errdefer steps.deinit(b.allocator);

    // This is the exe used to generate some build data.
    const build_data_exe = b.addExecutable(.{
@@ -49,7 +49,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
                    "share/terminfo/ghostty.terminfo",
            );

-            try steps.append(&source_install.step);
+            try steps.append(b.allocator, &source_install.step);
        }

        // Windows doesn't have the binaries below.
@@ -73,7 +73,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
                    "share/terminfo/ghostty.termcap",
            );

-            try steps.append(&cap_install.step);
+            try steps.append(b.allocator, &cap_install.step);
        }

        // Compile the terminfo source into a terminfo database
@@ -99,7 +99,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
                .{ b.install_path, terminfo_share_dir },
            ));

-            try steps.append(&mkdir_step.step);
+            try steps.append(b.allocator, &mkdir_step.step);

            // Use cp -R instead of Step.InstallDir because we need to preserve
            // symlinks in the terminfo database. Zig's InstallDir step doesn't
@@ -109,7 +109,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            copy_step.addFileArg(path);
            copy_step.addArg(b.fmt("{s}/share", .{b.install_path}));
            copy_step.step.dependOn(&mkdir_step.step);
-            try steps.append(&copy_step.step);
+            try steps.append(b.allocator, &copy_step.step);
        }
    }

@@ -121,7 +121,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_subdir = b.pathJoin(&.{ "ghostty", "shell-integration" }),
            .exclude_extensions = &.{".md"},
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // Themes
@@ -132,7 +132,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_subdir = b.pathJoin(&.{ "ghostty", "themes" }),
            .exclude_extensions = &.{".md"},
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // Fish shell completions
@@ -147,7 +147,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_dir = .prefix,
            .install_subdir = "share/fish/vendor_completions.d",
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // zsh shell completions
@@ -162,7 +162,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_dir = .prefix,
            .install_subdir = "share/zsh/site-functions",
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // bash shell completions
@@ -177,7 +177,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_dir = .prefix,
            .install_subdir = "share/bash-completion/completions",
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // Vim and Neovim plugin
@@ -210,14 +210,14 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_dir = .prefix,
            .install_subdir = "share/vim/vimfiles",
        });
-        try steps.append(&vim_step.step);
+        try steps.append(b.allocator, &vim_step.step);

        const neovim_step = b.addInstallDirectory(.{
            .source_dir = wf.getDirectory(),
            .install_dir = .prefix,
            .install_subdir = "share/nvim/site",
        });
-        try steps.append(&neovim_step.step);
+        try steps.append(b.allocator, &neovim_step.step);
    }

    // Sublime syntax highlighting for bat cli tool
@@ -237,7 +237,7 @@ pub fn init(b: *std.Build, cfg: *const Config) !GhosttyResources {
            .install_dir = .prefix,
            .install_subdir = "share/bat/syntaxes",
        });
-        try steps.append(&install_step.step);
+        try steps.append(b.allocator, &install_step.step);
    }

    // App (Linux)
@@ -286,16 +286,17 @@ fn addLinuxAppResources(
    // second element of the tuple.
    const Template = struct { std.Build.LazyPath, []const u8 };
    const templates: []const Template = templates: {
-        var ts: std.ArrayList(Template) = .init(b.allocator);
+        var ts: std.ArrayList(Template) = .empty;
+        defer ts.deinit(b.allocator);

        // Desktop file so that we have an icon and other metadata
-        try ts.append(.{
+        try ts.append(b.allocator, .{
            b.path("dist/linux/app.desktop.in"),
            b.fmt("share/applications/{s}.desktop", .{app_id}),
        });

        // Service for DBus activation.
-        try ts.append(.{
+        try ts.append(b.allocator, .{
            if (cfg.flatpak)
                b.path("dist/linux/dbus.service.flatpak.in")
            else
@@ -320,7 +321,7 @@ fn addLinuxAppResources(
        // See the following code:
        //
        // https://github.com/flatpak/xdg-desktop-portal/blob/7d4d48cf079147c8887da17ec6c3954acd5a285c/src/xdp-utils.c#L152-L220
-        if (!cfg.flatpak) try ts.append(.{
+        if (!cfg.flatpak) try ts.append(b.allocator, .{
            b.path("dist/linux/systemd.service.in"),
            b.fmt(
                "{s}/systemd/user/app-{s}.service",
@@ -333,12 +334,12 @@ fn addLinuxAppResources(

        // AppStream metainfo so that application has rich metadata
        // within app stores
-        try ts.append(.{
+        try ts.append(b.allocator, .{
            b.path("dist/linux/com.mitchellh.ghostty.metainfo.xml.in"),
            b.fmt("share/metainfo/{s}.metainfo.xml", .{app_id}),
        });

-        break :templates ts.items;
+        break :templates try ts.toOwnedSlice(b.allocator);
    };

    // Process all our templates
@@ -361,65 +362,65 @@ fn addLinuxAppResources(
            template[1],
        );

-        try steps.append(&copy.step);
+        try steps.append(b.allocator, &copy.step);
    }

    // Right click menu action for Plasma desktop
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("dist/linux/ghostty_dolphin.desktop"),
        "share/kio/servicemenus/com.mitchellh.ghostty.desktop",
    ).step);

    // Right click menu action for Nautilus. Note that this _must_ be named
    // `ghostty.py`. Using the full app id causes problems (see #5468).
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("dist/linux/ghostty_nautilus.py"),
        "share/nautilus-python/extensions/ghostty.py",
    ).step);

    // Various icons that our application can use, including the icon
    // that will be used for the desktop.
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/16.png"),
        "share/icons/hicolor/16x16/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/32.png"),
        "share/icons/hicolor/32x32/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/128.png"),
        "share/icons/hicolor/128x128/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/256.png"),
        "share/icons/hicolor/256x256/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/512.png"),
        "share/icons/hicolor/512x512/apps/com.mitchellh.ghostty.png",
    ).step);
    // Flatpaks only support icons up to 512x512.
    if (!cfg.flatpak) {
-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            b.path("images/gnome/1024.png"),
            "share/icons/hicolor/1024x1024/apps/com.mitchellh.ghostty.png",
        ).step);
    }

-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/32.png"),
        "share/icons/hicolor/16x16@2/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/64.png"),
        "share/icons/hicolor/32x32@2/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/256.png"),
        "share/icons/hicolor/128x128@2/apps/com.mitchellh.ghostty.png",
    ).step);
-    try steps.append(&b.addInstallFile(
+    try steps.append(b.allocator, &b.addInstallFile(
        b.path("images/gnome/512.png"),
        "share/icons/hicolor/256x256@2/apps/com.mitchellh.ghostty.png",
    ).step);
--- a/src/build/GhosttyWebdata.zig
+++ b/src/build/GhosttyWebdata.zig
@@ -12,8 +12,8 @@ pub fn init(
    b: *std.Build,
    deps: *const SharedDeps,
 ) !GhosttyWebdata {
-    var steps = std.ArrayList(*std.Build.Step).init(b.allocator);
-    errdefer steps.deinit();
+    var steps: std.ArrayList(*std.Build.Step) = .empty;
+    errdefer steps.deinit(b.allocator);

    {
        const webgen_config = b.addExecutable(.{
@@ -43,7 +43,7 @@ pub fn init(
        const webgen_config_step = b.addRunArtifact(webgen_config);
        const webgen_config_out = webgen_config_step.captureStdOut();

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            webgen_config_out,
            "share/ghostty/webdata/config.mdx",
        ).step);
@@ -52,8 +52,10 @@ pub fn init(
    {
        const webgen_actions = b.addExecutable(.{
            .name = "webgen_actions",
-            .root_source_file = b.path("src/main.zig"),
-            .target = b.graph.host,
+            .root_module = b.createModule(.{
+                .root_source_file = b.path("src/main.zig"),
+                .target = b.graph.host,
+            }),
        });
        deps.help_strings.addImport(webgen_actions);

@@ -72,7 +74,7 @@ pub fn init(
        const webgen_actions_step = b.addRunArtifact(webgen_actions);
        const webgen_actions_out = webgen_actions_step.captureStdOut();

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            webgen_actions_out,
            "share/ghostty/webdata/actions.mdx",
        ).step);
@@ -81,8 +83,10 @@ pub fn init(
    {
        const webgen_commands = b.addExecutable(.{
            .name = "webgen_commands",
-            .root_source_file = b.path("src/main.zig"),
-            .target = b.graph.host,
+            .root_module = b.createModule(.{
+                .root_source_file = b.path("src/main.zig"),
+                .target = b.graph.host,
+            }),
        });
        deps.help_strings.addImport(webgen_commands);

@@ -101,7 +105,7 @@ pub fn init(
        const webgen_commands_step = b.addRunArtifact(webgen_commands);
        const webgen_commands_out = webgen_commands_step.captureStdOut();

-        try steps.append(&b.addInstallFile(
+        try steps.append(b.allocator, &b.addInstallFile(
            webgen_commands_out,
            "share/ghostty/webdata/commands.mdx",
        ).step);
--- a/src/build/MetallibStep.zig
+++ b/src/build/MetallibStep.zig
@@ -44,7 +44,7 @@ pub fn create(b: *std.Build, opts: Options) ?*MetallibStep {
    const self = b.allocator.create(MetallibStep) catch @panic("OOM");

    const min_version = if (opts.target.query.os_version_min) |v|
-        b.fmt("{}", .{v.semver})
+        b.fmt("{f}", .{v.semver})
    else switch (opts.target.result.os.tag) {
        .macos => "10.14",
        .ios => "11.0",
--- a/src/build/SharedDeps.zig
+++ b/src/build/SharedDeps.zig
@@ -113,8 +113,8 @@ pub fn add(

    // We maintain a list of our static libraries and return it so that
    // we can build a single fat static library for the final app.
-    var static_libs = LazyPathList.init(b.allocator);
-    errdefer static_libs.deinit();
+    var static_libs: LazyPathList = .empty;
+    errdefer static_libs.deinit(b.allocator);

    // WARNING: This is a hack!
    // If we're cross-compiling to Darwin then we don't add any deps.
@@ -154,6 +154,7 @@ pub fn add(
            } else {
                step.linkLibrary(freetype_dep.artifact("freetype"));
                try static_libs.append(
+                    b.allocator,
                    freetype_dep.artifact("freetype").getEmittedBin(),
                );
            }
@@ -178,6 +179,7 @@ pub fn add(
            } else {
                step.linkLibrary(harfbuzz_dep.artifact("harfbuzz"));
                try static_libs.append(
+                    b.allocator,
                    harfbuzz_dep.artifact("harfbuzz").getEmittedBin(),
                );
            }
@@ -201,6 +203,7 @@ pub fn add(
            } else {
                step.linkLibrary(fontconfig_dep.artifact("fontconfig"));
                try static_libs.append(
+                    b.allocator,
                    fontconfig_dep.artifact("fontconfig").getEmittedBin(),
                );
            }
@@ -218,6 +221,7 @@ pub fn add(
        })) |libpng_dep| {
            step.linkLibrary(libpng_dep.artifact("png"));
            try static_libs.append(
+                b.allocator,
                libpng_dep.artifact("png").getEmittedBin(),
            );
        }
@@ -231,6 +235,7 @@ pub fn add(
        })) |zlib_dep| {
            step.linkLibrary(zlib_dep.artifact("z"));
            try static_libs.append(
+                b.allocator,
                zlib_dep.artifact("z").getEmittedBin(),
            );
        }
@@ -250,6 +255,7 @@ pub fn add(
        } else {
            step.linkLibrary(oniguruma_dep.artifact("oniguruma"));
            try static_libs.append(
+                b.allocator,
                oniguruma_dep.artifact("oniguruma").getEmittedBin(),
            );
        }
@@ -270,6 +276,7 @@ pub fn add(
        } else {
            step.linkLibrary(glslang_dep.artifact("glslang"));
            try static_libs.append(
+                b.allocator,
                glslang_dep.artifact("glslang").getEmittedBin(),
            );
        }
@@ -289,6 +296,7 @@ pub fn add(
        } else {
            step.linkLibrary(spirv_cross_dep.artifact("spirv_cross"));
            try static_libs.append(
+                b.allocator,
                spirv_cross_dep.artifact("spirv_cross").getEmittedBin(),
            );
        }
@@ -307,6 +315,7 @@ pub fn add(
            );
            step.linkLibrary(sentry_dep.artifact("sentry"));
            try static_libs.append(
+                b.allocator,
                sentry_dep.artifact("sentry").getEmittedBin(),
            );

@@ -316,6 +325,7 @@ pub fn add(
                .optimize = optimize,
            })) |breakpad_dep| {
                try static_libs.append(
+                    b.allocator,
                    breakpad_dep.artifact("breakpad").getEmittedBin(),
                );
            }
@@ -443,6 +453,7 @@ pub fn add(
                macos_dep.artifact("macos"),
            );
            try static_libs.append(
+                b.allocator,
                macos_dep.artifact("macos").getEmittedBin(),
            );
        }
@@ -461,6 +472,7 @@ pub fn add(
        })) |libintl_dep| {
            step.linkLibrary(libintl_dep.artifact("intl"));
            try static_libs.append(
+                b.allocator,
                libintl_dep.artifact("intl").getEmittedBin(),
            );
        }
@@ -473,7 +485,10 @@ pub fn add(
    })) |cimgui_dep| {
        step.root_module.addImport("cimgui", cimgui_dep.module("cimgui"));
        step.linkLibrary(cimgui_dep.artifact("cimgui"));
-        try static_libs.append(cimgui_dep.artifact("cimgui").getEmittedBin());
+        try static_libs.append(
+            b.allocator,
+            cimgui_dep.artifact("cimgui").getEmittedBin(),
+        );
    }

    // Fonts
@@ -697,6 +712,7 @@ pub fn addSimd(
        })) |simdutf_dep| {
            m.linkLibrary(simdutf_dep.artifact("simdutf"));
            if (static_libs) |v| try v.append(
+                b.allocator,
                simdutf_dep.artifact("simdutf").getEmittedBin(),
            );
        }
@@ -708,7 +724,10 @@ pub fn addSimd(
        .optimize = optimize,
    })) |highway_dep| {
        m.linkLibrary(highway_dep.artifact("highway"));
-        if (static_libs) |v| try v.append(highway_dep.artifact("highway").getEmittedBin());
+        if (static_libs) |v| try v.append(
+            b.allocator,
+            highway_dep.artifact("highway").getEmittedBin(),
+        );
    }

    // utfcpp - This is used as a dependency on our hand-written C++ code
@@ -717,7 +736,10 @@ pub fn addSimd(
        .optimize = optimize,
    })) |utfcpp_dep| {
        m.linkLibrary(utfcpp_dep.artifact("utfcpp"));
-        if (static_libs) |v| try v.append(utfcpp_dep.artifact("utfcpp").getEmittedBin());
+        if (static_libs) |v| try v.append(
+            b.allocator,
+            utfcpp_dep.artifact("utfcpp").getEmittedBin(),
+        );
    }

    // SIMD C++ files
@@ -761,16 +783,20 @@ pub fn gtkNgDistResources(
    const gresource_xml = gresource_xml: {
        const xml_exe = b.addExecutable(.{
            .name = "generate_gresource_xml",
-            .root_source_file = b.path("src/apprt/gtk/build/gresource.zig"),
-            .target = b.graph.host,
+            .root_module = b.createModule(.{
+                .root_source_file = b.path("src/apprt/gtk/build/gresource.zig"),
+                .target = b.graph.host,
+            }),
        });
        const xml_run = b.addRunArtifact(xml_exe);

        // Run our blueprint compiler across all of our blueprint files.
        const blueprint_exe = b.addExecutable(.{
            .name = "gtk_blueprint_compiler",
-            .root_source_file = b.path("src/apprt/gtk/build/blueprint.zig"),
-            .target = b.graph.host,
+            .root_module = b.createModule(.{
+                .root_source_file = b.path("src/apprt/gtk/build/blueprint.zig"),
+                .target = b.graph.host,
+            }),
        });
        blueprint_exe.linkLibC();
        blueprint_exe.linkSystemLibrary2("gtk4", dynamic_link_opts);
--- a/src/build/UnicodeTables.zig
+++ b/src/build/UnicodeTables.zig
@@ -21,6 +21,9 @@ pub fn init(b: *std.Build, uucode_tables: std.Build.LazyPath) !UnicodeTables {
            .omit_frame_pointer = false,
            .unwind_tables = .sync,
        }),
+
+        // TODO: x86_64 self-hosted crashes
+        .use_llvm = true,
    });

    const symbols_exe = b.addExecutable(.{
@@ -32,6 +35,9 @@ pub fn init(b: *std.Build, uucode_tables: std.Build.LazyPath) !UnicodeTables {
            .omit_frame_pointer = false,
            .unwind_tables = .sync,
        }),
+
+        // TODO: x86_64 self-hosted crashes
+        .use_llvm = true,
    });

    if (b.lazyDependency("uucode", .{
--- a/src/build/docker/debian/Dockerfile
+++ b/src/build/docker/debian/Dockerfile
@@ -29,10 +29,10 @@ COPY ./build.zig /src
 # Install zig
 # https://ziglang.org/download/

-RUN export ZIG_VERSION=$(sed -n -e 's/^.*requireZig("\(.*\)").*$/\1/p' build.zig) && curl -L -o /tmp/zig.tar.xz "https://ziglang.org/download/$ZIG_VERSION/zig-linux-$(uname -m)-$ZIG_VERSION.tar.xz" && \
+RUN export ZIG_VERSION=$(sed -n -e 's/^.*requireZig("\(.*\)").*$/\1/p' build.zig) && curl -L -o /tmp/zig.tar.xz "https://ziglang.org/download/$ZIG_VERSION/zig-$(uname -m)-linux-$ZIG_VERSION.tar.xz" && \
    tar -xf /tmp/zig.tar.xz -C /opt && \
    rm /tmp/zig.tar.xz && \
-    ln -s "/opt/zig-linux-$(uname -m)-$ZIG_VERSION/zig" /usr/local/bin/zig
+    ln -s "/opt/zig-$(uname -m)-linux-$ZIG_VERSION/zig" /usr/local/bin/zig

 COPY . /src

--- a/src/build/mdgen/main_ghostty_1.zig
+++ b/src/build/mdgen/main_ghostty_1.zig
@@ -2,12 +2,15 @@ const std = @import("std");
 const gen = @import("mdgen.zig");

 pub fn main() !void {
-    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    var gpa: std.heap.GeneralPurposeAllocator(.{}) = .init;
    const alloc = gpa.allocator();

-    const writer = std.io.getStdOut().writer();
+    var buffer: [1024]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const writer = &stdout_writer.interface;
    try gen.substitute(alloc, @embedFile("ghostty_1_header.md"), writer);
    try gen.genActions(writer);
    try gen.genConfig(writer, true);
    try gen.substitute(alloc, @embedFile("ghostty_1_footer.md"), writer);
+    try writer.flush();
 }
--- a/src/build/mdgen/main_ghostty_5.zig
+++ b/src/build/mdgen/main_ghostty_5.zig
@@ -2,12 +2,15 @@ const std = @import("std");
 const gen = @import("mdgen.zig");

 pub fn main() !void {
-    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    var gpa: std.heap.GeneralPurposeAllocator(.{}) = .init;
    const alloc = gpa.allocator();

-    const output = std.io.getStdOut().writer();
-    try gen.substitute(alloc, @embedFile("ghostty_5_header.md"), output);
-    try gen.genConfig(output, false);
-    try gen.genKeybindActions(output);
-    try gen.substitute(alloc, @embedFile("ghostty_5_footer.md"), output);
+    var buffer: [1024]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const writer = &stdout_writer.interface;
+    try gen.substitute(alloc, @embedFile("ghostty_5_header.md"), writer);
+    try gen.genConfig(writer, false);
+    try gen.genKeybindActions(writer);
+    try gen.substitute(alloc, @embedFile("ghostty_5_footer.md"), writer);
+    try writer.flush();
 }
--- a/src/build/mdgen/mdgen.zig
+++ b/src/build/mdgen/mdgen.zig
@@ -5,7 +5,7 @@ const Config = @import("../../config/Config.zig");
 const Action = @import("../../cli/ghostty.zig").Action;
 const KeybindAction = @import("../../input/Binding.zig").Action;

-pub fn substitute(alloc: std.mem.Allocator, input: []const u8, writer: anytype) !void {
+pub fn substitute(alloc: std.mem.Allocator, input: []const u8, writer: *std.Io.Writer) !void {
    const output = try alloc.alloc(u8, std.mem.replacementSize(
        u8,
        input,
@@ -18,7 +18,7 @@ pub fn substitute(alloc: std.mem.Allocator, input: []const u8, writer: anytype)
    try writer.writeAll(output);
 }

-pub fn genConfig(writer: anytype, cli: bool) !void {
+pub fn genConfig(writer: *std.Io.Writer, cli: bool) !void {
    try writer.writeAll(
        \\
        \\# CONFIGURATION OPTIONS
@@ -48,7 +48,7 @@ pub fn genConfig(writer: anytype, cli: bool) !void {
    }
 }

-pub fn genActions(writer: anytype) !void {
+pub fn genActions(writer: *std.Io.Writer) !void {
    try writer.writeAll(
        \\
        \\# COMMAND LINE ACTIONS
@@ -83,7 +83,7 @@ pub fn genActions(writer: anytype) !void {
    }
 }

-pub fn genKeybindActions(writer: anytype) !void {
+pub fn genKeybindActions(writer: *std.Io.Writer) !void {
    try writer.writeAll(
        \\
        \\# KEYBIND ACTIONS
--- a/src/build/webgen/main_actions.zig
+++ b/src/build/webgen/main_actions.zig
@@ -3,6 +3,8 @@ const help_strings = @import("help_strings");
 const helpgen_actions = @import("../../input/helpgen_actions.zig");

 pub fn main() !void {
-    const output = std.io.getStdOut().writer();
-    try helpgen_actions.generate(output, .markdown, true, std.heap.page_allocator);
+    var buffer: [2048]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
+    try helpgen_actions.generate(stdout, .markdown, true, std.heap.page_allocator);
 }
--- a/src/build/webgen/main_commands.zig
+++ b/src/build/webgen/main_commands.zig
@@ -3,14 +3,16 @@ const Action = @import("../../cli/ghostty.zig").Action;
 const help_strings = @import("help_strings");

 pub fn main() !void {
-    const output = std.io.getStdOut().writer();
-    try genActions(output);
+    var buffer: [2048]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
+    try genActions(stdout);
 }

 // Note: as a shortcut for defining inline editOnGithubLinks per cli action the user
 // is directed to the folder view on Github. This includes a README pointing them to
 // the files to edit.
-pub fn genActions(writer: anytype) !void {
+pub fn genActions(writer: *std.Io.Writer) !void {
    // Write the header
    try writer.writeAll(
        \\---
--- a/src/build/webgen/main_config.zig
+++ b/src/build/webgen/main_config.zig
@@ -3,11 +3,13 @@ const Config = @import("../../config/Config.zig");
 const help_strings = @import("help_strings");

 pub fn main() !void {
-    const output = std.io.getStdOut().writer();
-    try genConfig(output);
+    var buffer: [2048]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
+    try genConfig(stdout);
 }

-pub fn genConfig(writer: anytype) !void {
+pub fn genConfig(writer: *std.Io.Writer) !void {
    // Write the header
    try writer.writeAll(
        \\---
@@ -122,7 +124,7 @@ pub fn genConfig(writer: anytype) !void {
    }
 }

-fn endBlock(writer: anytype, block: anytype) !void {
+fn endBlock(writer: *std.Io.Writer, block: anytype) !void {
    if (block) |v| switch (v) {
        .text => {},
        .code => try writer.writeAll("```\n"),
--- a/src/cli/args.zig
+++ b/src/cli/args.zig
@@ -162,10 +162,11 @@ pub fn parse(
                error.InvalidField => "unknown field",
                error.ValueRequired => formatValueRequired(T, arena_alloc, key) catch "value required",
                error.InvalidValue => formatInvalidValue(T, arena_alloc, key, value) catch "invalid value",
-                else => try std.fmt.allocPrintZ(
+                else => try std.fmt.allocPrintSentinel(
                    arena_alloc,
                    "unknown error {}",
                    .{err},
+                    0,
                ),
            };

@@ -235,14 +236,16 @@ fn formatValueRequired(
    comptime T: type,
    arena_alloc: std.mem.Allocator,
    key: []const u8,
-) std.mem.Allocator.Error![:0]const u8 {
-    var buf = std.ArrayList(u8).init(arena_alloc);
-    errdefer buf.deinit();
-    const writer = buf.writer();
+) std.Io.Writer.Error![:0]const u8 {
+    var stream: std.Io.Writer.Allocating = .init(arena_alloc);
+    const writer = &stream.writer;
+
    try writer.print("value required", .{});
    try formatValues(T, key, writer);
    try writer.writeByte(0);
-    return buf.items[0 .. buf.items.len - 1 :0];
+
+    const written = stream.written();
+    return written[0 .. written.len - 1 :0];
 }

 fn formatInvalidValue(
@@ -250,17 +253,23 @@ fn formatInvalidValue(
    arena_alloc: std.mem.Allocator,
    key: []const u8,
    value: ?[]const u8,
-) std.mem.Allocator.Error![:0]const u8 {
-    var buf = std.ArrayList(u8).init(arena_alloc);
-    errdefer buf.deinit();
-    const writer = buf.writer();
+) std.Io.Writer.Error![:0]const u8 {
+    var stream: std.Io.Writer.Allocating = .init(arena_alloc);
+    const writer = &stream.writer;
+
    try writer.print("invalid value \"{?s}\"", .{value});
    try formatValues(T, key, writer);
    try writer.writeByte(0);
-    return buf.items[0 .. buf.items.len - 1 :0];
+
+    const written = stream.written();
+    return written[0 .. written.len - 1 :0];
 }

-fn formatValues(comptime T: type, key: []const u8, writer: anytype) std.mem.Allocator.Error!void {
+fn formatValues(
+    comptime T: type,
+    key: []const u8,
+    writer: *std.Io.Writer,
+) std.Io.Writer.Error!void {
    @setEvalBranchQuota(2000);
    const typeinfo = @typeInfo(T);
    inline for (typeinfo.@"struct".fields) |f| {
@@ -324,7 +333,7 @@ pub fn parseIntoField(
                    return;
                }
                const raw = field.default_value_ptr orelse break :default;
-                const ptr: *const field.type = @alignCast(@ptrCast(raw));
+                const ptr: *const field.type = @ptrCast(@alignCast(raw));
                @field(dst, field.name) = ptr.*;
                return;
            }
@@ -542,8 +551,8 @@ pub fn parseAutoStruct(
        const key = std.mem.trim(u8, entry[0..idx], whitespace);

        // used if we need to decode a double-quoted string.
-        var buf: std.ArrayListUnmanaged(u8) = .empty;
-        defer buf.deinit(alloc);
+        var buf: std.Io.Writer.Allocating = .init(alloc);
+        defer buf.deinit();

        const value = value: {
            const value = std.mem.trim(u8, entry[idx + 1 ..], whitespace);
@@ -554,10 +563,9 @@ pub fn parseAutoStruct(
                value[value.len - 1] == '"')
            {
                // Decode a double-quoted string as a Zig string literal.
-                const writer = buf.writer(alloc);
-                const parsed = try std.zig.string_literal.parseWrite(writer, value);
+                const parsed = try std.zig.string_literal.parseWrite(&buf.writer, value);
                if (parsed == .failure) return error.InvalidValue;
-                break :value buf.items;
+                break :value buf.written();
            }

            break :value value;
@@ -586,7 +594,7 @@ pub fn parseAutoStruct(
                    break :default @field(default, field.name);
                } else {
                    const default_ptr = field.default_value_ptr orelse return error.InvalidValue;
-                    const typed_ptr: *const field.type = @alignCast(@ptrCast(default_ptr));
+                    const typed_ptr: *const field.type = @ptrCast(@alignCast(default_ptr));
                    break :default typed_ptr.*;
                }
            };
@@ -795,15 +803,13 @@ test "parse: diagnostic location" {
    } = .{};
    defer if (data._arena) |arena| arena.deinit();

-    var fbs = std.io.fixedBufferStream(
+    var r: std.Io.Reader = .fixed(
        \\a=42
        \\what
        \\b=two
    );
-    const r = fbs.reader();

-    const Iter = LineIterator(@TypeOf(r));
-    var iter: Iter = .{ .r = r, .filepath = "test" };
+    var iter: LineIterator = .{ .r = &r, .filepath = "test" };
    try parse(@TypeOf(data), testing.allocator, &data, &iter);
    try testing.expect(data._arena != null);
    try testing.expectEqualStrings("42", data.a);
@@ -1208,18 +1214,7 @@ test "parseIntoField: struct with basic fields" {
    try testing.expectEqual(84, data.value.b);
    try testing.expectEqual(24, data.value.c);

-    // Set with explicit default
-    data.value = try parseAutoStruct(
-        @TypeOf(data.value),
-        alloc,
-        "a:hello",
-        .{ .a = "oh no", .b = 42 },
-    );
-    try testing.expectEqualStrings("hello", data.value.a);
-    try testing.expectEqual(42, data.value.b);
-    try testing.expectEqual(12, data.value.c);
-
-    // Missing required field
+    // Missing require dfield
    try testing.expectError(
        error.InvalidValue,
        parseIntoField(@TypeOf(data), alloc, &data, "value", "a:hello"),
@@ -1395,115 +1390,119 @@ test "ArgsIterator" {
 /// Returns an iterator (implements "next") that reads CLI args by line.
 /// Each CLI arg is expected to be a single line. This is used to implement
 /// configuration files.
-pub fn LineIterator(comptime ReaderType: type) type {
-    return struct {
-        const Self = @This();
+pub const LineIterator = struct {
+    const Self = @This();

-        /// The maximum size a single line can be. We don't expect any
-        /// CLI arg to exceed this size. Can't wait to git blame this in
-        /// like 4 years and be wrong about this.
-        pub const MAX_LINE_SIZE = 4096;
+    /// The maximum size a single line can be. We don't expect any
+    /// CLI arg to exceed this size. Can't wait to git blame this in
+    /// like 4 years and be wrong about this.
+    pub const MAX_LINE_SIZE = 4096;

-        /// Our stateful reader.
-        r: ReaderType,
+    /// Our stateful reader.
+    r: *std.Io.Reader,

-        /// Filepath that is used for diagnostics. This is only used for
-        /// diagnostic messages so it can be formatted however you want.
-        /// It is prefixed to the messages followed by the line number.
-        filepath: []const u8 = "",
+    /// Filepath that is used for diagnostics. This is only used for
+    /// diagnostic messages so it can be formatted however you want.
+    /// It is prefixed to the messages followed by the line number.
+    filepath: []const u8 = "",

-        /// The current line that we're on. This is 1-indexed because
-        /// lines are generally 1-indexed in the real world. The value
-        /// can be zero if we haven't read any lines yet.
-        line: usize = 0,
+    /// The current line that we're on. This is 1-indexed because
+    /// lines are generally 1-indexed in the real world. The value
+    /// can be zero if we haven't read any lines yet.
+    line: usize = 0,

-        /// This is the buffer where we store the current entry that
-        /// is formatted to be compatible with the parse function.
-        entry: [MAX_LINE_SIZE]u8 = [_]u8{ '-', '-' } ++ ([_]u8{0} ** (MAX_LINE_SIZE - 2)),
+    /// This is the buffer where we store the current entry that
+    /// is formatted to be compatible with the parse function.
+    entry: [MAX_LINE_SIZE]u8 = [_]u8{ '-', '-' } ++ ([_]u8{0} ** (MAX_LINE_SIZE - 2)),

-        pub fn next(self: *Self) ?[]const u8 {
-            // TODO: detect "--" prefixed lines and give a friendlier error
-            const buf = buf: {
-                while (true) {
-                    // Read the full line
-                    var entry = self.r.readUntilDelimiterOrEof(self.entry[2..], '\n') catch |err| switch (err) {
-                        inline else => |e| {
-                            log.warn("cannot read from \"{s}\": {}", .{ self.filepath, e });
-                            return null;
-                        },
-                    } orelse return null;
+    pub fn init(reader: *std.Io.Reader) Self {
+        return .{ .r = reader };
+    }

-                    // Increment our line counter
-                    self.line += 1;
+    pub fn next(self: *Self) ?[]const u8 {
+        // First prime the reader.
+        // File readers at least are initialized with a size of 0,
+        // and this will actually prompt the reader to get the actual
+        // size of the file, which will be used in the EOF check below.
+        //
+        // This will also optimize reads down the line as we're
+        // more likely to beworking with buffered data.
+        self.r.fillMore() catch {};

-                    // Trim any whitespace (including CR) around it
-                    const trim = std.mem.trim(u8, entry, whitespace ++ "\r");
-                    if (trim.len != entry.len) {
-                        std.mem.copyForwards(u8, entry, trim);
-                        entry = entry[0..trim.len];
-                    }
+        var writer: std.Io.Writer = .fixed(self.entry[2..]);

-                    // Ignore blank lines and comments
-                    if (entry.len == 0 or entry[0] == '#') continue;
+        var entry = while (self.r.seek != self.r.end) {
+            // Reset write head
+            writer.end = 0;

-                    // Trim spaces around '='
-                    if (mem.indexOf(u8, entry, "=")) |idx| {
-                        const key = std.mem.trim(u8, entry[0..idx], whitespace);
-                        const value = value: {
-                            var value = std.mem.trim(u8, entry[idx + 1 ..], whitespace);
+            _ = self.r.streamDelimiterEnding(&writer, '\n') catch |e| {
+                log.warn("cannot read from \"{s}\": {}", .{ self.filepath, e });
+                return null;
+            };
+            _ = self.r.discardDelimiterInclusive('\n') catch {};

-                            // Detect a quoted string.
-                            if (value.len >= 2 and
-                                value[0] == '"' and
-                                value[value.len - 1] == '"')
-                            {
-                                // Trim quotes since our CLI args processor expects
-                                // quotes to already be gone.
-                                value = value[1 .. value.len - 1];
-                            }
+            var entry = writer.buffered();
+            self.line += 1;

-                            break :value value;
-                        };
+            // Trim any whitespace (including CR) around it
+            const trim = std.mem.trim(u8, entry, whitespace ++ "\r");
+            if (trim.len != entry.len) {
+                std.mem.copyForwards(u8, entry, trim);
+                entry = entry[0..trim.len];
+            }

-                        const len = key.len + value.len + 1;
-                        if (entry.len != len) {
-                            std.mem.copyForwards(u8, entry, key);
-                            entry[key.len] = '=';
-                            std.mem.copyForwards(u8, entry[key.len + 1 ..], value);
-                            entry = entry[0..len];
-                        }
-                    }
+            // Ignore blank lines and comments
+            if (entry.len == 0 or entry[0] == '#') continue;
+            break entry;
+        } else return null;

-                    break :buf entry;
+        if (mem.indexOf(u8, entry, "=")) |idx| {
+            const key = std.mem.trim(u8, entry[0..idx], whitespace);
+            const value = value: {
+                var value = std.mem.trim(u8, entry[idx + 1 ..], whitespace);
+
+                // Detect a quoted string.
+                if (value.len >= 2 and
+                    value[0] == '"' and
+                    value[value.len - 1] == '"')
+                {
+                    // Trim quotes since our CLI args processor expects
+                    // quotes to already be gone.
+                    value = value[1 .. value.len - 1];
                }
+
+                break :value value;
            };

-            // We need to reslice so that we include our '--' at the beginning
-            // of our buffer so that we can trick the CLI parser to treat it
-            // as CLI args.
-            return self.entry[0 .. buf.len + 2];
+            const len = key.len + value.len + 1;
+            if (entry.len != len) {
+                std.mem.copyForwards(u8, entry, key);
+                entry[key.len] = '=';
+                std.mem.copyForwards(u8, entry[key.len + 1 ..], value);
+                entry = entry[0..len];
+            }
        }

-        /// Returns a location for a diagnostic message.
-        pub fn location(
-            self: *const Self,
-            alloc: Allocator,
-        ) Allocator.Error!?diags.Location {
-            // If we have no filepath then we have no location.
-            if (self.filepath.len == 0) return null;
+        // We need to reslice so that we include our '--' at the beginning
+        // of our buffer so that we can trick the CLI parser to treat it
+        // as CLI args.
+        return self.entry[0 .. entry.len + 2];
+    }

-            return .{ .file = .{
-                .path = try alloc.dupe(u8, self.filepath),
-                .line = self.line,
-            } };
-        }
-    };
-}
+    /// Returns a location for a diagnostic message.
+    pub fn location(
+        self: *const Self,
+        alloc: Allocator,
+    ) Allocator.Error!?diags.Location {
+        // If we have no filepath then we have no location.
+        if (self.filepath.len == 0) return null;

-// Constructs a LineIterator (see docs for that).
-fn lineIterator(reader: anytype) LineIterator(@TypeOf(reader)) {
-    return .{ .r = reader };
-}
+        return .{ .file = .{
+            .path = try alloc.dupe(u8, self.filepath),
+            .line = self.line,
+        } };
+    }
+};

 /// An iterator valid for arg parsing from a slice.
 pub const SliceIterator = struct {
@@ -1526,7 +1525,7 @@ pub fn sliceIterator(slice: []const []const u8) SliceIterator {

 test "LineIterator" {
    const testing = std.testing;
-    var fbs = std.io.fixedBufferStream(
+    var reader: std.Io.Reader = .fixed(
        \\A
        \\B=42
        \\C
@@ -1541,7 +1540,7 @@ test "LineIterator" {
        \\F=  "value "
    );

-    var iter = lineIterator(fbs.reader());
+    var iter: LineIterator = .init(&reader);
    try testing.expectEqualStrings("--A", iter.next().?);
    try testing.expectEqualStrings("--B=42", iter.next().?);
    try testing.expectEqualStrings("--C", iter.next().?);
@@ -1554,9 +1553,9 @@ test "LineIterator" {

 test "LineIterator end in newline" {
    const testing = std.testing;
-    var fbs = std.io.fixedBufferStream("A\n\n");
+    var reader: std.Io.Reader = .fixed("A\n\n");

-    var iter = lineIterator(fbs.reader());
+    var iter: LineIterator = .init(&reader);
    try testing.expectEqualStrings("--A", iter.next().?);
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
@@ -1564,9 +1563,9 @@ test "LineIterator end in newline" {

 test "LineIterator spaces around '='" {
    const testing = std.testing;
-    var fbs = std.io.fixedBufferStream("A = B\n\n");
+    var reader: std.Io.Reader = .fixed("A = B\n\n");

-    var iter = lineIterator(fbs.reader());
+    var iter: LineIterator = .init(&reader);
    try testing.expectEqualStrings("--A=B", iter.next().?);
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
@@ -1574,18 +1573,18 @@ test "LineIterator spaces around '='" {

 test "LineIterator no value" {
    const testing = std.testing;
-    var fbs = std.io.fixedBufferStream("A = \n\n");
+    var reader: std.Io.Reader = .fixed("A = \n\n");

-    var iter = lineIterator(fbs.reader());
+    var iter: LineIterator = .init(&reader);
    try testing.expectEqualStrings("--A=", iter.next().?);
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
 }

 test "LineIterator with CRLF line endings" {
    const testing = std.testing;
-    var fbs = std.io.fixedBufferStream("A\r\nB = C\r\n");
+    var reader: std.Io.Reader = .fixed("A\r\nB = C\r\n");

-    var iter = lineIterator(fbs.reader());
+    var iter: LineIterator = .init(&reader);
    try testing.expectEqualStrings("--A", iter.next().?);
    try testing.expectEqualStrings("--B=C", iter.next().?);
    try testing.expectEqual(@as(?[]const u8, null), iter.next());
--- a/src/cli/boo.zig
+++ b/src/cli/boo.zig
@@ -6,7 +6,7 @@ const Allocator = std.mem.Allocator;
 const help_strings = @import("help_strings");
 const vaxis = @import("vaxis");

-const framedata = @import("framedata");
+const framedata = @embedFile("framedata");

 const vxfw = vaxis.vxfw;

@@ -218,17 +218,20 @@ var frames: []const []const u8 = undefined;

 /// Decompress the frames into a slice of individual frames
 fn decompressFrames(gpa: Allocator) !void {
-    var fbs = std.io.fixedBufferStream(framedata.compressed);
-    var list = std.ArrayList(u8).init(gpa);
+    var src: std.Io.Reader = .fixed(framedata);

-    try std.compress.flate.decompress(fbs.reader(), list.writer());
-    decompressed_data = try list.toOwnedSlice();
+    // var buf: [std.compress.flate.max_window_len]u8 = undefined;
+    var decompress: std.compress.flate.Decompress = .init(&src, .raw, &.{});

-    var frame_list = try std.ArrayList([]const u8).initCapacity(gpa, 235);
+    var out: std.Io.Writer.Allocating = .init(gpa);
+    _ = try decompress.reader.streamRemaining(&out.writer);
+    decompressed_data = try out.toOwnedSlice();
+
+    var frame_list: std.ArrayList([]const u8) = try .initCapacity(gpa, 235);

    var frame_iter = std.mem.splitScalar(u8, decompressed_data, '\x01');
    while (frame_iter.next()) |frame| {
-        try frame_list.append(frame);
+        try frame_list.append(gpa, frame);
    }
-    frames = try frame_list.toOwnedSlice();
+    frames = try frame_list.toOwnedSlice(gpa);
 }
--- a/src/cli/crash_report.zig
+++ b/src/cli/crash_report.zig
@@ -38,21 +38,35 @@ pub fn run(alloc_gpa: Allocator) !u8 {
        try args.parse(Options, alloc_gpa, &opts, &iter);
    }

+    var buffer: [1024]u8 = undefined;
+    var stdout_file: std.fs.File = .stdout();
+    var stdout_writer = stdout_file.writer(&buffer);
+    const stdout = &stdout_writer.interface;
+
+    const result = runInner(alloc, &stdout_file, stdout);
+    stdout.flush() catch {};
+    return result;
+}
+
+fn runInner(
+    alloc: Allocator,
+    stdout_file: *std.fs.File,
+    stdout: *std.Io.Writer,
+) !u8 {
    const crash_dir = try crash.defaultDir(alloc);
-    var reports = std.ArrayList(crash.Report).init(alloc);
+    var reports: std.ArrayList(crash.Report) = .empty;
+    errdefer reports.deinit(alloc);

    var it = try crash_dir.iterator();
-    while (try it.next()) |report| try reports.append(.{
+    while (try it.next()) |report| try reports.append(alloc, .{
        .name = try alloc.dupe(u8, report.name),
        .mtime = report.mtime,
    });

-    const stdout = std.io.getStdOut();
-
    // If we have no reports, then we're done. If we have a tty then we
    // print a message, otherwise we do nothing.
    if (reports.items.len == 0) {
-        if (std.posix.isatty(stdout.handle)) {
+        if (std.posix.isatty(stdout_file.handle)) {
            try stdout.writeAll("No crash reports! 👻\n");
        }
        return 0;
@@ -60,16 +74,15 @@ pub fn run(alloc_gpa: Allocator) !u8 {

    std.mem.sort(crash.Report, reports.items, {}, lt);

-    const writer = stdout.writer();
    for (reports.items) |report| {
        var buf: [128]u8 = undefined;
        const now = std.time.nanoTimestamp();
        const diff = now - report.mtime;
        const since = if (diff <= 0) "now" else s: {
            const d = Config.Duration{ .duration = @intCast(diff) };
-            break :s try std.fmt.bufPrint(&buf, "{s} ago", .{d.round(std.time.ns_per_s)});
+            break :s try std.fmt.bufPrint(&buf, "{f} ago", .{d.round(std.time.ns_per_s)});
        };
-        try writer.print("{s} ({s})\n", .{ report.name, since });
+        try stdout.print("{s} ({s})\n", .{ report.name, since });
    }

    return 0;
--- a/src/cli/diagnostics.zig
+++ b/src/cli/diagnostics.zig
@@ -16,7 +16,7 @@ pub const Diagnostic = struct {
    message: [:0]const u8,

    /// Write the full user-friendly diagnostic message to the writer.
-    pub fn write(self: *const Diagnostic, writer: anytype) !void {
+    pub fn format(self: *const Diagnostic, writer: *std.Io.Writer) !void {
        switch (self.location) {
            .none => {},
            .cli => |index| try writer.print("cli:{}:", .{index}),
@@ -157,11 +157,14 @@ pub const DiagnosticList = struct {
        errdefer _ = self.list.pop();

        if (comptime precompute_enabled) {
-            var buf = std.ArrayList(u8).init(alloc);
-            defer buf.deinit();
-            try diag.write(buf.writer());
+            var stream: std.Io.Writer.Allocating = .init(alloc);
+            defer stream.deinit();
+            diag.format(&stream.writer) catch |err| switch (err) {
+                // WriteFailed in this instance can only mean an OOM
+                error.WriteFailed => return error.OutOfMemory,
+            };

-            const owned: [:0]const u8 = try buf.toOwnedSliceSentinel(0);
+            const owned: [:0]const u8 = try stream.toOwnedSliceSentinel(0);
            errdefer alloc.free(owned);

            try self.precompute.messages.append(alloc, owned);
--- a/src/cli/edit_config.zig
+++ b/src/cli/edit_config.zig
@@ -47,7 +47,9 @@ pub fn run(alloc: Allocator) !u8 {
    // not using `exec` anymore and because this command isn't performance
    // critical where setting up the defer cleanup is a problem.

-    const stderr = std.io.getStdErr().writer();
+    var buffer: [1024]u8 = undefined;
+    var stderr_writer = std.fs.File.stderr().writer(&buffer);
+    const stderr = &stderr_writer.interface;

    var opts: Options = .{};
    defer opts.deinit();
@@ -58,6 +60,13 @@ pub fn run(alloc: Allocator) !u8 {
        try args.parse(Options, alloc, &opts, &iter);
    }

+    const result = runInner(alloc, stderr);
+    // Flushing *shouldn't* fail but...
+    stderr.flush() catch {};
+    return result;
+}
+
+fn runInner(alloc: Allocator, stderr: *std.Io.Writer) !u8 {
    // We load the configuration once because that will write our
    // default configuration files to disk. We don't use the config.
    var config = try Config.load(alloc);
@@ -133,23 +142,13 @@ pub fn run(alloc: Allocator) !u8 {
    // so this is not a big deal.
    comptime assert(builtin.link_libc);

-    var buf: std.ArrayListUnmanaged(u8) = .empty;
-    errdefer buf.deinit(alloc);
-
-    const writer = buf.writer(alloc);
-    var shellescape: internal_os.ShellEscapeWriter(std.ArrayListUnmanaged(u8).Writer) = .init(writer);
-    var shellescapewriter = shellescape.writer();
-
-    try writer.writeAll(editor);
-    try writer.writeByte(' ');
-    try shellescapewriter.writeAll(path);
-
-    const command = try buf.toOwnedSliceSentinel(alloc, 0);
-    defer alloc.free(command);
-
+    const editorZ = try alloc.dupeZ(u8, editor);
+    defer alloc.free(editorZ);
+    const pathZ = try alloc.dupeZ(u8, path);
+    defer alloc.free(pathZ);
    const err = std.posix.execvpeZ(
-        "sh",
-        &.{ "sh", "-c", command },
+        editorZ,
+        &.{ editorZ, pathZ },
        std.c.environ,
    );

--- a/src/cli/ghostty.zig
+++ b/src/cli/ghostty.zig
@@ -107,12 +107,18 @@ pub const Action = enum {
                    // for all commands by just changing this one place.

                    if (std.mem.eql(u8, field.name, @tagName(self))) {
-                        const stdout = std.io.getStdOut().writer();
+                        var buffer: [1024]u8 = undefined;
+                        var stdout_writer = std.fs.File.stdout().writer(&buffer);
+                        const stdout = &stdout_writer.interface;
                        const text = @field(help_strings.Action, field.name) ++ "\n";
                        stdout.writeAll(text) catch |write_err| {
                            std.log.warn("failed to write help text: {}\n", .{write_err});
                            break :err 1;
                        };
+                        stdout.flush() catch |flush_err| {
+                            std.log.warn("failed to flush help text: {}\n", .{flush_err});
+                            break :err 1;
+                        };

                        break :err 0;
                    }
--- a/src/cli/help.zig
+++ b/src/cli/help.zig
@@ -30,7 +30,9 @@ pub fn run(alloc: Allocator) !u8 {
        try args.parse(Options, alloc, &opts, &iter);
    }

-    const stdout = std.io.getStdOut().writer();
+    var buffer: [2048]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
    try stdout.writeAll(
        \\Usage: ghostty [+action] [options]
        \\
@@ -70,6 +72,7 @@ pub fn run(alloc: Allocator) !u8 {
        \\where `<action>` is one of actions listed above.
        \\
    );
+    try stdout.flush();

    return 0;
 }
--- a/Show More
+++ b/Show More