NixOS + Rust `/usr/bin/clang` not found

Help
1

Hello, so far enjoyed NixOS, seeking for help:

Recently I tried to setup Rust development environment in my NixOS and when compiling the project with cargo run, I get error: linker `/usr/bin/clang` not found in my nix-shell.

which clang returns the correct path of clang in nix store.

I wonder why rust, or some rust modules are using the absolute path /usr/bin/clang to find clang in my case. And if it’s rust or some rust modules’ problem what is the workaround. (like adding a link to clang in /usr/bin manually, or some nix functions to create it for me?)

BTW, I tried rustup and moz overlay for rust installation, both have this problem.

2

I don’t think Rust would default to “clang” at all, but rather to cc / ld, which will often point to GCC instead. However, we do not know what project you are compiling. If a particular crate’s build scripts expect /usr/bin/clang, you will unfortunately need to adjust that crate.

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3

There are a number of issues on nixpkgs’ github repo linked to this seems in connection mostly to building to webassembly and/or building on macOS, some fixed and some still open. Have you had a look at them?

4

Any chance you could share the repository you’re working on? I’ve run into this with amethyst before, usually the project’s build.rs will be what’s doing things like hard-coding paths to binaries and libraries.

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5

I use Rust on NixOS, maybe I can help you. Can you copy the dependencies of your project?

6

Thanks for the help!!

shell.nix

let
  moz_overlay = import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz);
  nixpkgs = import <nixpkgs> { overlays = [ moz_overlay ]; };
in
  with nixpkgs;
  stdenv.mkDerivation {
    name = "moz_overlay_shell";
    buildInputs = [
      nixpkgs.latest.rustChannels.nightly.rust
      clang llvm llvmPackages.libclang lld # lld is recommended from bevy
      pkgconfig udev alsaLib lutris # from this line and below are dependencies of bevy
      x11 xorg.libXcursor xorg.libXrandr xorg.libXi
      vulkan-tools vulkan-headers vulkan-loader vulkan-validation-layers
    ];
    shellHook = ''
      export LIBCLANG_PATH="${pkgs.llvmPackages.libclang}/lib"; // I searched this discourse and added this but still failing.
    '';
  }

Cargo.toml

[package]
name = "my_bevy_game"
version = "0.1.0"
edition = "2018"

[dependencies]
bevy = { version = "0.5.0"}

The error:

error: linker `/usr/bin/clang` not found
  |
  = note: No such file or directory (os error 2)

error: could not compile `serde_derive` due to previous error

(Sometimes it’s libm)

The weird thing is that once ```/usr/bin/clang` not found`` happens once, it will happen all the time no matter how I change the dependencies. (I changed it to no dependencies the error still happens)

7

It doesn’t looks like particular problem in some crates though, cargo build --verbose has

     Running `rustc --crate-name build_script_build --edition=2018 /home/lliu/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.2.1/build.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="default"' -C metadata=1f5ec41f42fa5445 -C extra-filename=-1f5ec41f42fa5445 --out-dir /home/lliu/personal/my_bevy_game/target/debug/build/libm-1f5ec41f42fa5445 -C linker=/usr/bin/clang -L dependency=/home/lliu/personal/my_bevy_game/target/debug/deps --cap-lints allow -Clink-arg=-fuse-ld=lld -Zshare-generics=y`

-C linker=/usr/bin/clang is in every line.

8

Alright, I found the reason, it’s my own bad.

The bevy tutorial recommend a rust config and it’s setting the linker path.

I’m good to go on now, thanks for all the help!

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