Pass in rust-overlay for creating rust-bin.

flake.nix

@@ -35,9 +35,9 @@
           pkgs = import nixpkgs {
             inherit system overlays;
           };
-          rustToolchain =
-            (pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml).override
-              { targets = [ "wasm32-unknown-unknown" ]; };
+          rustToolchain = (pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml).override {
+            targets = [ "wasm32-unknown-unknown" ];
+          };
         in
         {
           default = pkgs.mkShell {
@@ -96,6 +96,7 @@
                 bindgenTarget ? null,
               }:
               (organicScope.callPackage ./nix/package.nix {
+                inherit rust-overlay;
                 targetBins = [
                   "wasm"
                 ];
@@ -128,7 +129,12 @@
                 );
           in
           {
-            library = (organicScope.callPackage ./nix/package.nix { buildLib = true; }).overrideAttrs (
+            library =
+              (organicScope.callPackage ./nix/package.nix {
+                inherit rust-overlay;
+                buildLib = true;
+              }).overrideAttrs
+                (
                   old:
                   let
                   in
@@ -140,6 +146,7 @@
                   }
                 );
             devTools = organicScope.callPackage ./nix/package.nix {
+              inherit rust-overlay;
               targetBins = [
                 "parse"
                 "compare"

nix/package.nix

@@ -1,8 +1,8 @@
 {
   hello,
   lib,
-  makeRustPlatform,
-  pkgsBuildHost,
+  pkgs,
+  rust-overlay,
 
   targetBins ? [ ],
   features ? [ ],
@@ -12,7 +12,11 @@
 }:
 let
   cargoToml = (lib.importTOML ../Cargo.toml);
-  rustToolchain = (pkgsBuildHost.rust-bin.fromRustupToolchainFile ../rust-toolchain.toml).override (
+  rustPlatformFor =
+    pkgs:
+    let
+      rust-bin = rust-overlay.lib.mkRustBin { } pkgs;
+      rustToolchain = (rust-bin.fromRustupToolchainFile ../rust-toolchain.toml).override (
         if cargoBuildTarget != null then
           {
             targets = [ cargoBuildTarget ];
@@ -21,7 +25,7 @@ let
           { }
       );
       baseRustPlatform = (
-    makeRustPlatform {
+        pkgs.makeRustPlatform {
           cargo = rustToolchain;
           rustc = rustToolchain;
         }
@@ -39,7 +43,10 @@ let
         else
           baseRustPlatform;
     in
-rustPlatform.buildRustPackage (
+    rustPlatform;
+in
+(rustPlatformFor pkgs).buildRustPackage (
+  # rustPlatform.buildRustPackage (
   {
     pname = "organic";
     version = cargoToml.package.version;