From 60448993c599009213ba4618bc053e81e83577c3 Mon Sep 17 00:00:00 2001
From: Reed Krantz <programming@krantz.one>
Date: Wed, 10 Jun 2026 21:21:16 -0500
Subject: [PATCH] refactor(rust): update the way the rust.srcToolchain default
 works and also some defaultText

---
 rust/default.nix | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/rust/default.nix b/rust/default.nix
index 84b0731..0028e8b 100644
--- a/rust/default.nix
+++ b/rust/default.nix
@@ -29,7 +29,7 @@
         manifest = (lib.importTOML "${src}/Cargo.toml").package;
 
         craneLib =
-          if builtins.pathExists cfg.srcToolchain
+          if cfg.srcToolchain != null && builtins.pathExists cfg.srcToolchain
           then
             (inputs.crane.mkLib (pkgs.extend inputs.rust-overlay.overlays.default)).overrideToolchain (
               p: p.rust-bin.fromRustupToolchainFile cfg.srcToolchain
@@ -61,18 +61,26 @@
             description = "A path to the filtered directory of the root of the crate.";
             type = lib.types.path;
             default = craneLib.cleanCargoSource cfg.src;
-            defaultText = lib.literalExpression "config.krantz.rust.craneLib cfg.src";
+            defaultText = lib.literalExpression "config.krantz.rust.craneLib.cleanCargoSource cfg.src";
             example = lib.literalExpression "./.";
           };
           srcToolchain = lib.mkOption {
             description = "A path to the rust-toolchain(.toml) file for the repo. Will use the toolchain from nixpkgs if the file does not exist.";
-            type = lib.types.path;
-            default = "${
+            type = lib.types.nullOr lib.types.path;
+            default =
               if cfg.src != null
-              then cfg.src
-              else "/dev/null"
-            }/rust-toolchain.toml";
-            defaultText = lib.literalExpression "cfg.src + \"/rust-toolchain.toml\"";
+              then cfg.src + "/rust-toolchain.toml"
+              else null;
+            defaultText =
+              lib.literalExpression
+              /*
+              nix
+              */
+              ''
+                if cfg.src != null
+                then cfg.src + "/rust-toolchain.toml"
+                else null;
+              '';
             example = lib.literalExpression "./rust-toolchain";
           };