Merge pull request #27780 from tilpner/overridable-buildenv

Make buildEnv overridable

pkgs/build-support/buildenv/default.nix

···
 
 { buildPackages, runCommand, lib }:
 
-{ name
+lib.makeOverridable
+({ name
 
 , # The manifest file (if any).  A symlink $out/manifest will be
   # created to it.
···
   ''
     ${buildPackages.perl}/bin/perl -w ${./builder.pl}
     eval "$postBuild"
-  ''
+  '')