message: nix-shell: install rust-analyzer
diff: with import <nixpkgs> { };
  -
  -stdenv.mkDerivation rec {
  +let
  + nixpkgs_with_rust_analyzer = import (fetchGit {
  + name = "nixpkgs_with_rust_analyzer";
  + url = "https://github.com/oxalica/nixpkgs/";
  + ref = "rust-analyzer";
  + rev = "bde9289415bae0e62e67072e22f5666da4c3a9f5";
  + }) { };
  +in stdenv.mkDerivation rec {
  name = "xain-fl";
  buildInputs = [
  + nixpkgs_with_rust_analyzer.rust-analyzer
  pkgs.latest.rustChannels.nightly.rust
  pkgs.cargo-edit
  pkgs.cargo-tree
  