feat: Add Nix build for nixfd

Builds my [nixfd][] tool for searching a cached version of the Nix package
list.

[nixfd]: https://github.com/tazjin/nixfd

pkgs/nixfd.nix

@@ -0,0 +1,28 @@
+with import <nixpkgs> {};
+
+# Build and install my nixfd tool.
+with rustPlatform;
+
+buildRustPackage rec {
+  name = "nixfd-${version}";
+  version = "0.1.0";
+
+  # This hash is of course total bullshit due to the dummy libc dependency
+  # caused by:
+  # https://github.com/NixOS/nixpkgs/issues/22737
+  depsSha256 = "0iihnyq50qbq0fkvcj5jxilcw7d3bwd1x3gwcq0mzrcah23say0j";
+
+  src = fetchFromGitHub {
+    owner = "tazjin";
+    repo = "nixfd";
+    rev = "dbadc9ef8486070f26677154fa032a47d732b7a9";
+    sha256 = "162301lc4znlqbansmaw9sla1rwi2s5nfmhl3z752n6aj2gcvz89";
+  };
+
+  meta = with stdenv.lib; {
+    description = "Tired of waiting for nix-env -qaP?";
+    homepage = https://github.com/tazjin/nixfd;
+    license = licenses.mit;
+    platforms = platforms.all;
+  };
+}