update nix & project files to use mold

.cargo/config.toml

@@ -0,0 +1,11 @@
+# Target specification ensures these settings apply only when building for this architecture.
+[target.x86_64-unknown-linux-gnu]
+
+# Tell rustc to use 'clang' (from nativeBuildInputs) as the linker driver.
+linker = "clang"
+
+# Pass flags to rustc (-C flag).
+# 'link-arg' passes the subsequent argument directly to the linker driver ('clang').
+# '-fuse-ld=mold' tells clang to use the 'mold' executable as the actual linker.
+# Nix ensures the 'mold' found in PATH is the wrapped version from 'mold-wrapped'.
+rustflags = ["-C", "link-arg=-fuse-ld=mold"]

Cargo.toml

@@ -26,7 +26,3 @@ inherits = "release"
 opt-level = "s"
 # Strip all debugging information from the binary to slightly reduce file size.
 strip = "debuginfo"
-
-[target.x86_64-unknown-linux-gnu]
-linker = "clang"
-rustflags = ["-C", "link-arg=-fuse-ld=/usr/bin/mold"]

shell.nix

@@ -1,15 +1,23 @@
-{ pkgs ? import <nixpkgs> { } }:
+{ pkgs? import <nixpkgs> { } }:
 
 with pkgs;
 
 mkShell rec {
+  # Tools needed to build the project
   nativeBuildInputs = [
     pkg-config
+    # Add the wrapped mold linker
+    mold-wrapped
+    # Add clang, needed to drive mold via -fuse-ld=
+    llvmPackages.clang # Or just `clang`
   ];
+
+  # Libraries the project links against or needs at runtime
   buildInputs = [
     udev alsa-lib vulkan-loader
     xorg.libX11 xorg.libXcursor xorg.libXi xorg.libXrandr # To use the x11 feature
     libxkbcommon wayland # To use the wayland feature
   ];
+
   LD_LIBRARY_PATH = lib.makeLibraryPath buildInputs;
 }