WIP try crate2nix but doesn't work

flake.lock

@@ -80,7 +80,11 @@
           "cargo2nix",
           "flake-utils"
         ],
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": [
+          "cargo2nix",
+          "rust-overlay"
+        ]
       }
     },
     "rust-overlay": {

flake.nix

@@ -29,34 +29,49 @@
   };
 
   inputs.flake-utils.follows = "cargo2nix/flake-utils";
+  inputs.rust-overlay.follows = "cargo2nix/rust-overlay";
 
-  outputs = { self, nixpkgs, cargo2nix, flake-utils, ... }:
+  outputs = { self, nixpkgs, cargo2nix, flake-utils, rust-overlay, ... }:
     let
       git_version = self.lastModifiedDate;
       compile = import ./nix/compile.nix;
     in
     flake-utils.lib.eachDefaultSystem (system:
       let
-        pkgs = nixpkgs.legacyPackages.${system};
+        pkgs = import nixpkgs {
+          inherit system;
+        }; 
+        nativeBuild = 
+          pkgs.callPackage ./Cargo.nix {
+            release = false;
+          };
+        crossBuild = target:
+          let
+            crossPkgs = import nixpkgs {
+              inherit system;
+              crossSystem = {
+                config = target;
+              };
+              overlays = [ rust-overlay.overlays.default ];
+            }; 
+            buildRustCrateForPkgs = pkgs: pkgs.buildRustCrate.override {
+                rustc = pkgs.rust-bin.stable."1.77.0".default;
+                cargo = pkgs.rust-bin.stable."1.77.0".default;
+              };
+          in
+            crossPkgs.callPackage ./Cargo.nix {
+              inherit buildRustCrateForPkgs;
+              release = false;
+            };
       in
       {
         packages =
-          let
-            packageFor = target: (compile {
-              inherit system git_version target;
-              pkgsSrc = nixpkgs;
-              cargo2nixOverlay = cargo2nix.overlays.default;
-              release = true;
-            }).workspace.garage { compileMode = "build"; };
-          in
           {
             # default = native release build
-            default = packageFor null;
+            default = nativeBuild.workspaceMembers."garage".build;
-            # other = cross-compiled, statically-linked builds
+            # cross-platform builds
-            amd64 = packageFor "x86_64-unknown-linux-musl";
+            amd64 = (crossBuild "x86_64-linux").workspaceMembers."garage".build;
-            i386 = packageFor "i686-unknown-linux-musl";
+            i386 = (crossBuild "i686-linux").workspaceMembers."garage".build;
-            arm64 = packageFor "aarch64-unknown-linux-musl";
-            arm = packageFor "armv6l-unknown-linux-musl";
           };
 
         # ---- developpment shell, for making native builds only ----