From 306981fd2a62f07086998024c5d8df199b5b6bba Mon Sep 17 00:00:00 2001
From: Kiana Sheibani <kiana.a.sheibani@gmail.com>
Date: Sun, 22 Feb 2026 05:28:22 -0500
Subject: [PATCH] fix(rust): use proper `withComponents` toolchain

Using this function properly links the `rustup` components together,
allowing e.g. `rust-analyzer` to find the location of `rust-src`.
---
 rust/cargo-nightly/crane+fenix/flake.nix       |  4 ++--
 rust/cargo-nightly/crane+fenix/shell.nix       |  5 +----
 rust/cargo-nightly/crane+fenix/toolchain.nix   | 13 +++++++++++++
 rust/cargo-nightly/nixpkgs+fenix/shell.nix     |  5 +----
 rust/cargo-nightly/nixpkgs+fenix/toolchain.nix | 13 +++++++++++++
 5 files changed, 30 insertions(+), 10 deletions(-)
 create mode 100644 rust/cargo-nightly/crane+fenix/toolchain.nix
 create mode 100644 rust/cargo-nightly/nixpkgs+fenix/toolchain.nix

diff --git a/rust/cargo-nightly/crane+fenix/flake.nix b/rust/cargo-nightly/crane+fenix/flake.nix
index 23f75ed..8c66a64 100644
--- a/rust/cargo-nightly/crane+fenix/flake.nix
+++ b/rust/cargo-nightly/crane+fenix/flake.nix
@@ -16,7 +16,7 @@
       packages = eachSystem (system:
         let
           pkgs = nixpkgs.legacyPackages.${system};
-          toolchain = fenix.packages.${system}.${fenixToolchain}.toolchain;
+          toolchain = import ./toolchain.nix fenix.packages.${system} "build";
         in {
           hello = pkgs.callPackage ./package.nix {
             craneLib = (crane.mkLib pkgs).overrideToolchain toolchain;
@@ -33,7 +33,7 @@
       checks = eachSystem (system:
         let
           pkgs = nixpkgs.legacyPackages.${system};
-          toolchain = fenix.packages.${system}.${fenixToolchain}.toolchain;
+          toolchain = import ./toolchain.nix fenix.packages.${system} "check";
           craneLib = (crane.mkLib pkgs).overrideToolchain toolchain;
           crate = self.packages.${system}.default;
         in {
diff --git a/rust/cargo-nightly/crane+fenix/shell.nix b/rust/cargo-nightly/crane+fenix/shell.nix
index 92837d7..9e1ce21 100644
--- a/rust/cargo-nightly/crane+fenix/shell.nix
+++ b/rust/cargo-nightly/crane+fenix/shell.nix
@@ -1,16 +1,13 @@
 { pkgs ? import <nixpkgs> {},
   crane ? builtins.getFlake "github:ipetkov/crane",
   fenix ? builtins.getFlake "github:nix-community/fenix",
-  fenixToolchain ? "default"
 }:
 let
-  fenixPkgs = fenix.packages.${pkgs.system};
-  toolchain = fenixPkgs.${fenixToolchain}.toolchain;
+  toolchain = import ./toolchain.nix fenix.packages.${pkgs.stdenv.hostPlatform.system} "dev";
   craneLib = (crane.mkLib pkgs).overrideToolchain toolchain;
 in craneLib.devShell {
   packages = [
     toolchain
-    fenixPkgs.rust-analyzer
     pkgs.lldb_21
   ];
 }
diff --git a/rust/cargo-nightly/crane+fenix/toolchain.nix b/rust/cargo-nightly/crane+fenix/toolchain.nix
new file mode 100644
index 0000000..7a79139
--- /dev/null
+++ b/rust/cargo-nightly/crane+fenix/toolchain.nix
@@ -0,0 +1,13 @@
+fenixPkgs: proc:
+fenixPkgs.complete.withComponents ([
+  "rustc"
+  "rust-std"
+  "cargo"
+] ++ (if proc != "build" then [
+  "clippy"
+] else []) ++ (if proc == "dev" then [
+  "rust-docs"
+  "rustfmt"
+  "rust-src"
+  "rust-analyzer"
+] else []))
diff --git a/rust/cargo-nightly/nixpkgs+fenix/shell.nix b/rust/cargo-nightly/nixpkgs+fenix/shell.nix
index b9167c1..3a56a4f 100644
--- a/rust/cargo-nightly/nixpkgs+fenix/shell.nix
+++ b/rust/cargo-nightly/nixpkgs+fenix/shell.nix
@@ -1,15 +1,12 @@
 { pkgs ? import <nixpkgs> {},
   fenix ? builtins.getFlake "github:nix-community/fenix",
-  fenixToolchain ? "default"
 }:
 let
   inherit (pkgs) mkShellNoCC;
-  fenixPkgs = fenix.packages.${pkgs.system};
-  toolchain = fenixPkgs.${fenixToolchain}.toolchain;
+  toolchain = import ./toolchain.nix fenix.packages.${pkgs.stdenv.hostPlatform.system} "dev";
 in mkShellNoCC {
   packages = [
     toolchain
-    fenixPkgs.rust-analyzer
     pkgs.lldb_21
   ];
 }
diff --git a/rust/cargo-nightly/nixpkgs+fenix/toolchain.nix b/rust/cargo-nightly/nixpkgs+fenix/toolchain.nix
new file mode 100644
index 0000000..7a79139
--- /dev/null
+++ b/rust/cargo-nightly/nixpkgs+fenix/toolchain.nix
@@ -0,0 +1,13 @@
+fenixPkgs: proc:
+fenixPkgs.complete.withComponents ([
+  "rustc"
+  "rust-std"
+  "cargo"
+] ++ (if proc != "build" then [
+  "clippy"
+] else []) ++ (if proc == "dev" then [
+  "rust-docs"
+  "rustfmt"
+  "rust-src"
+  "rust-analyzer"
+] else []))