How to setup Rust development on NixOS?

[flosse]

I installed helix with nix-env -iA nixos.helix and nix-env -iA nixos.rust-analyzer and I added this to languages.toml:

[[language]]
name = "rust"

[language.config]
checkOnSave = { command = "clippy" }

But nothing happens.

hx --health:

[the-mikedavis]

But nothing happens.

Can you explain what you are trying to do? You should be able to open a rust project like the helix codebase and use rust-analyzer features like going to definitions or references and seeing diagnostics. You can also check the log file to see if there are any errors from opening a rust file https://github.com/helix-editor/helix/wiki/FAQ#access-the-log-file

[flosse]

Thanks for the fast reply!

Now I see... there are lot's of errors in the log. I will do a little investigation.

[flosse]

Is there a way to show errors directly in helix? Or do I always have to open the log files?

2022-12-28T14:47:46.980 helix_lsp::transport [ERROR] err <- "[ERROR rust_analyzer::lsp_utils] rust-analyzer failed to load workspace: Failed to find sysroot for Cargo.toml file /home/mk/dev-public/clean-architecture-with-rust/Cargo.toml. Is rust-src installed?: can't load standa
     rd library from sysroot\n"
2022-12-28T14:47:46.980 helix_lsp::transport [ERROR] err <- "/nix/store/kjw0nq5hdxnlpa1s916l6bkfj2dwq6ak-rust-1.66.0-2022-12-12-69f9c33d7\n"
2022-12-28T14:47:46.980 helix_lsp::transport [ERROR] err <- "(discovered via `rustc --print sysroot`)\n"
2022-12-28T14:47:46.980 helix_lsp::transport [ERROR] err <- "try installing the Rust source the same way you installed rustc\n"
2022-12-28T14:47:46.980 helix_lsp::transport [ERROR] err <- "\n"

[the-mikedavis]

Those lines are printed to stderr by rust-analyzer. I think you may need to install rustc and maybe cargo for rust-analyzer to work properly.

[flosse]

It seems to be related to mozilla/nixpkgs-mozilla#263

[flosse]

It looks like this solves the problem:

  (rustChannel.rust.override { extensions = ["rust-src" "rust-analysis"]; })

Here is a full example of a shell.nix:

let
  moz_overlay = import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz);
  pkgs = import <nixpkgs> { overlays = [ moz_overlay ]; };
  rustChannel = pkgs.rustChannelOf {
     channel = "stable";
  };
  rust = (rustChannel.rust.override {
    targets = [
      "wasm32-unknown-unknown" # required for the web-app
    ];
    extensions = ["rust-src" "rust-analysis"];
  });

  # required for the desktop app
  runtime_deps = with pkgs; [
      libGL
  ] ++ (with pkgs.xorg; [
      libX11
      libXcursor
      libXrandr
      libXi
  ]);

in
  with pkgs;
  mkShell {
    buildInputs = [

      rust
      pkgconfig

      # required for the web-app
      sassc

      # required for the desktop
      freetype
      expat
      fontconfig
    ];

    LD_LIBRARY_PATH = "${lib.makeLibraryPath runtime_deps}";
}