diff --git a/compiler/deps.nim b/compiler/deps.nim
index 3e09a5e40f..f46a7f01da 100644
--- a/compiler/deps.nim
+++ b/compiler/deps.nim
@@ -1249,15 +1249,21 @@ proc commandIc*(conf: ConfigRef) =
     let nifmake = findNifmake()
     # Build the per-module rules concurrently: nifmake fans out all commands at
     # each DAG depth via execProcesses (defaults to all cores). Cold builds are
-    # otherwise serial (one child at a time) and leave the machine idle. Opt out
-    # with `-d:icNoParallel` (e.g. for readable, non-interleaved child output
-    # when debugging a build), or cap the concurrency with `-d:icJobs:N` — an
-    # uncapped fan-out across many cores can exhaust RAM on a large project
-    # (each `nim m`/`cg` child holds its own module graph), which nifmake's own
-    # `-j:N` exists to bound.
+    # otherwise serial (one child at a time) and leave the machine idle. An
+    # uncapped fan-out across many cores can exhaust RAM on a large project (each
+    # `nim m`/`cg` child holds its own module graph), which nifmake's own `-j:N`
+    # exists to bound. Concurrency is chosen (highest precedence first):
+    #   * `-d:icNoParallel`      -> serial (readable, non-interleaved child output)
+    #   * `-d:icJobs:N`          -> cap at N (legacy IC-tuning define)
+    #   * `--parallelBuild:N`    -> cap at N (the standard Nim build-parallelism
+    #                               flag; a no-op for `nim c` under IC, so we give
+    #                               it meaning here — lets Nimbus devs pick their
+    #                               own value without a `-d:` define)
+    #   * otherwise              -> uncapped (all cores)
     let parallel =
       if isDefined(conf, "icNoParallel"): ""
       elif isDefined(conf, "icJobs"): " --parallel:" & conf.symbols["icJobs"]
+      elif conf.numberOfProcessors > 0: " --parallel:" & $conf.numberOfProcessors
       else: " --parallel"
 
     # Phase 1 — frontend (nifler + `nim m`), run to a discovery fixpoint.
diff --git a/compiler/icnifcore.nim b/compiler/icnifcore.nim
index b0cdbdf745..b4ed9d064f 100644
--- a/compiler/icnifcore.nim
+++ b/compiler/icnifcore.nim
@@ -219,8 +219,18 @@ proc collectBifStrLits*(path: string): seq[string] =
   ## string literal it holds, in order — the binary analogue of the old nifstreams
   ## scan that collected `StrLit`s. Keeps nifcore types out of `deps.nim`, which
   ## only needs the recorded string list.
+  ##
+  ## Uses `loadFromFile` (a full read into owned memory) rather than the mmap-backed
+  ## `bif.load`, then CLOSES the handle. `bif.load` intentionally leaves the mapping
+  ## resident for the process lifetime; for the `nim ic` driver that reads these
+  ## sidecars while `nim m` children rewrite them, a lingering read mapping is a
+  ## Windows sharing violation: the child's `open(path, fmWrite)` fails with
+  ## `IOError: cannot open`. These sidecars are tiny, so the zero-copy mmap buys
+  ## nothing here anyway.
   result = @[]
-  var m = bif.load(path)
+  var f = open(path, fmRead)
+  var m = bif.loadFromFile(f)
+  close(f)
   var c = m.buf.beginRead()
   while c.hasMore:
     if c.kind == StrLit: result.add strVal(c)
diff --git a/compiler/typekeys.nim b/compiler/typekeys.nim
index 54092eb055..6c7ca51d7b 100644
--- a/compiler/typekeys.nim
+++ b/compiler/typekeys.nim
@@ -47,6 +47,11 @@ type
     CoConsiderOwned
     CoDistinct
     CoHashTypeInsideNode
+    CoPrecise                 # produce a FRONTEND-faithful, unique key (for the
+                              # stable NIF *name*, not hook dedup): keep distinctions
+                              # sem makes that the backend identity collapses — e.g.
+                              # an `int literal(x)` type carries its value so it does
+                              # not merge with `int`. See `getTypeKey`/`typeKeyHook`.
 
   TypeLoader* = proc (t: PType) {.nimcall.}
   SymLoader* = proc (s: PSym) {.nimcall.}
@@ -139,6 +144,20 @@ proc maybeImported(c: var Context; s: PSym; conf: ConfigRef) {.inline.} =
   if s != nil and {sfImportc, sfExportc} * s.flagsImpl != {}:
     c.symKey(s, conf)
 
+proc emitPreciseFlags(c: var Context; t: PType; flags: set[ConsiderFlag]) {.inline.} =
+  ## Under CoPrecise the NIF *name* must be as fine as `types.sameType`, which
+  ## compares `eqTypeFlags * flags` (see `sameFlags`). Without this a
+  ## `proc() {.gcsafe.}` keyed identically to `proc()`, and a `ref X not nil`
+  ## identically to `ref X` — the loader would then merge two frontend-distinct
+  ## types onto one NIF name. Emitted only for the naming path (CoPrecise); the
+  ## `setAttachedOp` hook key (no CoPrecise) is unaffected, so its byte layout is
+  ## unchanged.
+  if CoPrecise in flags:
+    let ef = eqTypeFlags * t.flagsImpl
+    if ef != {}:
+      withTree c.m, "´tflags":
+        for f in ef: c.m.addIntLit ord(f)
+
 proc backendTypeName(t: PType; conf: ConfigRef): string =
   ## Stable cross-module identity of a backend-minted (lower-stage) type: its
   ## serialized `@bk` NIF name (mirrors ast2nif.nifTypeName). A closure-env
@@ -229,6 +248,10 @@ proc typeKey(c: var Context; t: PType; flags: set[ConsiderFlag]; conf: ConfigRef
   of tyInt:
     withTree c.m, "i":
       c.m.addIntLit -1
+      # An `int literal(x)` type (nImpl holds the value) must stay distinct from
+      # plain `int` for the NIF name, else overload resolution breaks on reload.
+      if CoPrecise in flags and t.nImpl != nil:
+        c.m.addIntLit t.nImpl.intVal
       maybeImported(c, t.symImpl, conf)
   of tyInt8:
     withTree c.m, "i":
@@ -266,6 +289,14 @@ proc typeKey(c: var Context; t: PType; flags: set[ConsiderFlag]; conf: ConfigRef
     withTree c.m, "u":
       c.m.addIntLit 64
       maybeImported(c, t.symImpl, conf)
+  of tyFloat:
+    withTree c.m, "f":
+      c.m.addIntLit -1
+      # A `float literal(x)` type (nImpl = nkFloatLit) must stay distinct from
+      # plain `float`, just like the `int literal(x)` case above.
+      if CoPrecise in flags and t.nImpl != nil and t.nImpl.kind in {nkFloatLit..nkFloat64Lit}:
+        c.m.addFloatLit t.nImpl.floatVal
+      maybeImported(c, t.symImpl, conf)
   of tyObject, tyEnum:
     if t.typeInstImpl != nil:
       # prevent against infinite recursions here, see bug #8883:
@@ -381,6 +412,9 @@ proc typeKey(c: var Context; t: PType; flags: set[ConsiderFlag]; conf: ConfigRef
 
       c.m.addIdent toNifTag(t.callConvImpl)
       if tfVarargs in t.flagsImpl: c.m.addIdent "´varargs"
+      # `.gcsafe`/`.noSideEffect` (in eqTypeFlags) distinguish proc types under
+      # sameType, so they must distinguish the NIF name too.
+      emitPreciseFlags(c, t, flags)
   of tyArray:
     withTree c.m, toNifTag(t.kind):
       if t.sonsImpl.len == 0:
@@ -395,6 +429,9 @@ proc typeKey(c: var Context; t: PType; flags: set[ConsiderFlag]; conf: ConfigRef
         c.typeKey t.sonsImpl[i], flags, conf
       if tfNotNil in t.flagsImpl and CoType notin flags:
         c.m.addIdent "´notnil"
+      # tfNotNil/tfVarIsPtr/tfIsOutParam (eqTypeFlags) part of sameType identity
+      # for ref/ptr/var/lent/sink; the hook path (no CoPrecise) keeps its layout.
+      emitPreciseFlags(c, t, flags)
 
 proc typeKey*(t: PType; conf: ConfigRef; tl: TypeLoader; sl: SymLoader): string =
   var c: Context = Context(m: createMangler(30, -1), tl: tl, sl: sl,
diff --git a/koch.nim b/koch.nim
index fe75164526..4a3f4ae9ae 100644
--- a/koch.nim
+++ b/koch.nim
@@ -16,11 +16,11 @@ const
   ChecksumsStableCommit = "5c132cd332cce5d64a0da9ac3e4c9664313dccb4" # 0.2.2
   SatStableCommit = "9d52513b3c68bfb929dbd687d4fb2836cfee6936"
 
-  NimonyStableCommit = "557b865192e25e8e76ce4ccc81c6ea71676e92e7" # unversioned \
+  NimonyStableCommit = "6f9ac6655dc6724ae4e5ccb93b8123c18d54391a" # unversioned \
     # Note that Nimony uses Nim as a git submodule but we don't want to install
     # Nimony's dependency to Nim as we are Nim. So a `git clone` without --recursive
     # is **required** here.
-    # Commit from 2026-07-01 -- contains a critical feature addition from nifmake for us
+    # Commit from 2026-07-03 -- .bif files are memory mapped too
 
   # examples of possible values for fusion: #head, #ea82b54, 1.2.3
   FusionStableHash = "#562467452b32cb7a97410ea177f083e6d8405734"