Override stdenv version

[jdahm]

Is it possible to override the stdenv version? I see this but it looks like the version isn't possible to set. I have a use-case in helix where some C compiler flags are used that may only be supported in clang > 11 versions.

[90-008]

If you mean the compiler version, that is possible through setting the cCompiler argument under [package.metadata.nix] in Cargo.toml, to something like clang etc. (a compiler package attribute path). You can't set this from nix code (yet), and it's not documented (although it should have been).

nix-cargo-integration uses stdenvNoCc and provides compiler through what the user specifies. I'm aware this is not ideal, so I will introduce a way to set stdenv.

[jdahm]

I'd like to set cCompiler via [package.metadata.nix] as you say or as an argument to overrides in nixCargoIntegration.lib.makeOutputs such as:

overrides = {
  packageMetadata = _: { cCompiler = "clang"; };
  ...
};

The problem is that in both cases I don't know how to access the system type. Some system checks are exposed through nixCargoIntegration later in common.pkgs.stdenv (e.g. isDarwin, etc.) but I don't seem to have access to that when setting packageMetadata. Can you think of a way to get at that there or in the Cargo.toml file for [package.metadata.nix]? Thanks for the help!

[90-008]

I opened #70 for this. It adds a new overrides.cCompiler that nix-cargo-integration supports, which can be used to set the C compiler that will be used. You can check the manual in that PR to see how to use it.

[90-008]

@jdahm just mentioning you to make sure you see this :)

[jdahm]

Thanks! This seems to be working on helix-editor/helix#1789. I'm just sorting out another issue there.

[NickHu]

Is this still possible in the new version?