musl-based toolchains are missing libgcc runtime dependency

[aaronmondal]

The pkgs.pkgsMusl.rust-bin.xxx toolchains mostly work fine, but (at least) rustdoc and cargo clippy instacrash with a missing libgcc_s.so.1. It seems like the musl stdenvs don't ship the libgcc package which supplies libgcc_s.so.1. This makes sense, but apparently the musl rust linux binaries were built against a dynamically linked libgcc_s.

The changes from #121 don't seem to work in this case.

This also affects pkgsCross.musl64.

On x86_64-unknown-linux-gnu, something that kinda-sorta works around the issue is adding LD_LIBRARY_PATH=${pkgs.pkgsMusl.libgcc} to a devShell. But that breaks all other non-musl packages as they expect a libgcc_s built against glibc.

Is there some way to explicitly add the libgcc runtime dependency? If possible I'd like to avoid pkgsStatic as it looks like that's not a cached package set and would incur massive upfront compilation of a static GCC toolchain.

Noticed in TraceMachina/nativelink#749

cc @RaitoBezarius

[wwilson]

Are you sure that this has fully solved the problem? I am still getting this on the latest revision of this repo:

nix-repl> :b pkgs.pkgsStatic.rust-bin.stable."1.77.2".minimal
error: builder for '/nix/store/6rzir020q8228jcp86ihqgwm1lp5w9cq-cargo-1.77.2-x86_64-unknown-linux-musl.drv' failed with exit code 1;
last 10 log lines:
> setting interpreter of /nix/store/nzlzxqh61w1hqp5ljj6gfr8pw8mbmz8k-cargo-1.77.2-x86_64-unknown-linux-musl/bin/cargo
> searching for dependencies of /nix/store/nzlzxqh61w1hqp5ljj6gfr8pw8mbmz8k-cargo-1.77.2-x86_64-unknown-linux-musl/bin/cargo
> libgcc_s.so.1 -> not found!
> auto-patchelf: 1 dependencies could not be satisfied
> error: auto-patchelf could not satisfy dependency libgcc_s.so.1 wanted by /nix/store/nzlzxqh61w1hqp5ljj6gfr8pw8mbmz8k-cargo-1.77.2-x86_64-unknown-linux-musl/bin/cargo
> auto-patchelf failed to find all the required dependencies.
> Add the missing dependencies to --libs or use --ignore-missing="foo.so.1 bar.so etc.so".
> /nix/store/kl8vsdrmbdf55ggn8hs0wi8agkfmvmwr-stdenv-linux/setup: line 74: pop_var_context: head of shell_variables not a function context
> /nix/store/kl8vsdrmbdf55ggn8hs0wi8agkfmvmwr-stdenv-linux/setup: line 1446: pop_var_context: head of shell_variables not a function context
> /nix/store/kl8vsdrmbdf55ggn8hs0wi8agkfmvmwr-stdenv-linux/setup: line 1549: pop_var_context: head of shell_variables not a function context
For full logs, run 'nix log /nix/store/6rzir020q8228jcp86ihqgwm1lp5w9cq-cargo-1.77.2-x86_64-unknown-linux-musl.drv'.
error: 1 dependencies of derivation '/nix/store/c30pm608jcdjyhcvml35zpnx39i2c5lw-rust-minimal-1.77.2.drv' failed to build

Incidentally, offering an "ultra-minimal" attribute that has rustc and rust-std but no cargo could be another way around for people who want to build with a static rust toolchain.

[oxalica]

:b pkgs.pkgsStatic.rust-bin.stable."1.77.2".minimal

I assume you want to make a toolchain that produces static binary, not a toolchain itself being static (which is impossible, because it's downloaded from upstream and it's shipped as dynamic binaries). So what you need is pkgs.pkgsStatic.buildPackages.rust-bin.stable."1.77.2".minimal. I can confirm it does build and run well. It can also compile code into static binaries via rustc --target=x86_64-unknown-linux-musl.

[wwilson]

Oh, you're right! Thank you!