Are you saying it already is an unconditional extra dep in the native bootstrap? Then I don't we need this bit at all!

Are you saying it already is an unconditional extra dep in the native bootstrap?

Not quite. See 3b8e3c1. It is a dependency of native stdenv, and therefore changes to it cause everything everywhere to rebuild. However it is only a direct dependency (i.e. hooks applied) of those packages which are part of stdenv itself.

The point of my comment above was that this PR will not increase the number of rebuilds caused by future gnu-config version bumps.

3b8e3c1#diff-bf918d7f48f6a34a4a1acb33373dee717cff2c3f5503a7ca41d90e5f289faf1eR615 doesn't that line make it part of the final stdenv / used by anything which is built with that stdenv?

3b8e3c1#diff-bf918d7f48f6a34a4a1acb33373dee717cff2c3f5503a7ca41d90e5f289faf1eR615 doesn't that line make it part of the final stdenv / used by anything which is built with that stdenv?

You're right.

I forgot that stdenv doesn't copy stdenv.mkDerivation doesn't prepend defaultNativeBuildInputs to the resulting nativeBuildInputs. The additional dependencies are added in bash, not in Nix code.

I guess they are really propagated native build inputs, propagated from stdenv.

My only remaining concern is that setup.sh tries to be clever and filter out any nativeBuildInputs that can't be executed on the buildPlatform.

In spite of the fact that it's a shell script, Nix believes that gnu-config has a meaningful execution platform associated with it. So it should get ignored at some point if you build a new stdenv with a different buildPlatform.

But I'm having a hard time making this happen.

I need to read findInputs() more closely. Grr, I wish we weren't doing this stuff in bash scripts...

Ah, I see.

You can never change the buildPlatform using pkgs/stdenv/cross.

That explains it.