`-iframework` wrongly passed to certain targets of GCC on Darwin host

[Ivan-Velickovic]

Describe the bug

When building certain ARM GCC cross-compilers on an x86 Darwin host, the -iframework flag is passed erroneously. The two cross-compilers that I have reproduced the issue for is aarch64-none-elf and aarch64-unknown-linux-gnu. Neither of these is targeting Darwin/macOS and hence the -iframework flag is expected to be unrecognisable to GCC.

I do not have access to an ARM64 Darwin machine, so do not know if the issue is reproducible there.

Steps To Reproduce

Steps to reproduce the behavior:

1. Enter a Nix shell using the cross-compiler with nix-shell -p pkgsCross.aarch64-embedded.buildPackages.gcc or nix-shell -p pkgsCross.aarch64-multiplatform.buildPackages.gcc
2. Run any command invoking the compiler, such as aarch64-none-elf-gcc --version
3. Observe the following behaviour: aarch64-none-elf-gcc: error: unrecognized command-line option ‘-iframework’

Expected behavior

No error message about -iframework.

Notify maintainers

@vcunat @Ericson2314

Metadata

 - system: `"x86_64-darwin"`
 - host os: `Darwin 21.6.0, macOS 10.16`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.16.1`
 - channels(root): `"nixpkgs"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixpkgs`

[Ivan-Velickovic]

Fairly new to Nix, apologies if I've gotten anything wrong.

[Ivan-Velickovic]

@Ericson2314 would you be able to help? Or could you point me into the direction of where to look to fix this? Thanks! Now notified maintainers in the original issue.

[Ivan-Velickovic]

Also observed this when trying to get a RISC-V toolchain as well.

[wucke13]

This is still relevant. Similar issues (some same cause, some with different cause):

• Compilation error: unrecognized command-line option ‘-iframework’ with avr-gcc on Apple silicon #339245
• -iframework flag added to cross-compiler (gcc) #283466 (User spliced in the pkgsCross by hand, so user error but same symptom)
• avr-gcc crashes because of -iframework option on macos #248206 (same as above)
• Unable to use avr-gcc #48205 (same as above)

[Liamolucko]

This seems to have been fixed by #346043, since there's no longer anything in stdenv which contains $out/Library/Frameworks and triggers this:

nixpkgs/pkgs/build-support/cc-wrapper/setup-hook.sh

Lines 75 to 77 in b0fb960

	if [ -d "$1/Library/Frameworks" ]; then
	export NIX_CFLAGS_COMPILE${role_post}+=" -iframework $1/Library/Frameworks"
	fi

Are there any other .frameworks in nixpkgs which still need that hook, or can it be removed now?

As for the more fundamental reason for the bug, I think what's happening is that when you put a cross compiler into nativeBuildInputs, you're saying to stdenv 'I declare that this package runs on this derivation's build platform, and targets this derivation's host platform'; and so as a result, it gives the cross compiler all the things which run on the host platform (buildInputs, which I think used to include darwin.CF by default) to link against, include headers from, etc. As a workaround, you can put the compiler in depsBuildTarget instead, since you probably don't have anything in depsTargetTarget for stdenv to try and pass to the cross compiler.

[Ivan-Velickovic]

Yes, that PR seems to have fixed. Thanks!