From 2f9359ae89622c2d95ef243d13251a310e94a199 Mon Sep 17 00:00:00 2001
From: quantimnot <quantimnot@users.noreply.github.com>
Date: Tue, 5 Oct 2021 02:55:36 -0400
Subject: [PATCH] Make compiler build more reproducible

Removed the compile time from the version output.
Added Git commit's author's datetime in UTC timezone.

Fixes #18508

See https://reproducible-builds.org/docs/timestamps/
See https://reproducible-builds.org/docs/source-date-epoch/
---
 compiler/commands.nim | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/compiler/commands.nim b/compiler/commands.nim
index a8caad9163..99e224e34a 100644
--- a/compiler/commands.nim
+++ b/compiler/commands.nim
@@ -43,8 +43,8 @@ type
 
 const
   HelpMessage = "Nim Compiler Version $1 [$2: $3]\n" &
-      "Compiled at $4\n" &
       "Copyright (c) 2006-" & copyrightYear & " by Andreas Rumpf\n"
+  gitCommit {.strdefine.} = gorge("TZ=UTC git log -n 1 --date=iso-local --format='%H (%cd)'").strip
 
 proc genFeatureDesc[T: enum](t: typedesc[T]): string {.compileTime.} =
   result = ""
@@ -91,10 +91,7 @@ proc writeVersionInfo(conf: ConfigRef; pass: TCmdLinePass) =
                                  CPU[conf.target.hostCPU].name, CompileDate]),
                {msgStdout})
 
-    const gitHash {.strdefine.} = gorge("git log -n 1 --format=%H").strip
-      # xxx move this logic to std/private/gitutils
-    when gitHash.len == 40:
-      msgWriteln(conf, "git hash: " & gitHash, {msgStdout})
+    msgWriteln(conf, "git commit: " & gitCommit, {msgStdout})
 
     msgWriteln(conf, "active boot switches:" & usedRelease & usedDanger &
       usedTinyC & useLinenoise &