Merge pull request #114944 from thefloweringash/darwin-arch-fixup

darwin.bootstrap_cmds: use correct arch in "mig"

pkgs/os-specific/darwin/apple-source-releases/bootstrap_cmds/default.nix

@@ -1,4 +1,4 @@
-{ lib, appleDerivation, yacc, flex }:
+{ lib, stdenv, appleDerivation, yacc, flex }:
 
 appleDerivation {
   nativeBuildInputs = [ yacc flex ];
@@ -26,7 +26,7 @@ appleDerivation {
     cp migcom.1 $out/share/man/man1
 
     substituteInPlace $out/bin/mig \
-      --replace 'arch=`/usr/bin/arch`' 'arch=i386' \
+      --replace 'arch=`/usr/bin/arch`' 'arch=${stdenv.targetPlatform.darwinArch}' \
       --replace '/usr/bin/' "" \
       --replace '/bin/rmdir' "rmdir" \
       --replace 'C=''${MIGCC}' "C=cc"