flake provide rust builds

Author: functora

rust/.envrc

@@ -1 +1,4 @@
-use flake .
+if [ -z "$NIX_DEVELOP_ONCE" ]; then
+    export NIX_DEVELOP_ONCE=1
+    nix develop
+fi

rust/flake.nix

@@ -14,6 +14,12 @@
     flake-utils.lib.eachDefaultSystem (
       system: let
         pkgs = nixpkgs.legacyPackages.${system};
+        mkRustPkg = pkg:
+          pkgs.rustPlatform.buildRustPackage {
+            name = pkg;
+            src = pkgs.nix-gitignore.gitignoreSource [] ./${pkg};
+            cargoLock.lockFile = ./${pkg}/Cargo.lock;
+          };
       in {
         devShells.default = pkgs.mkShell {
           packages = with pkgs; [
@@ -27,6 +33,10 @@
             rustfmt
           ];
         };
+        packages = {
+          rustell = mkRustPkg "rustell";
+          default = self.packages.${system}.rustell;
+        };
       }
     );
 }