nix: package+devShell: set strictDeps = true

flake.nix

@@ -28,6 +28,7 @@
     in {
       devShells = lib.mapAttrs (system: pkgs: {
         default = pkgs.mkShell {
+          strictDeps = true;
           buildInputs = [ pkgs.rust-bin.stable.${rustVersion}.default ];
         };
       }) pkgsFor;

nix/overlay.nix

@@ -0,0 +1,14 @@
+final: _:
+let
+  rust-bin = rust-overlay.lib.mkRustBin { } final;
+  rust-stable = rust-bin.stable.${rustVersion}.minimal;
+  rustPlatform = final.makeRustPlatform {
+    cargo = rust-stable;
+    rustc = rust-stable;
+  };
+in {
+  ${packageName} = final.callPackage ./nix/package.nix {
+    sourceRoot = self;
+    inherit rustPlatform;
+  };
+}

nix/package.nix

@@ -5,4 +5,5 @@ in rustPlatform.buildRustPackage {
   version = manifest.package.version;
   cargoLock.lockFile = "${sourceRoot}/Cargo.lock";
   src = lib.cleanSource sourceRoot;
+  strictDeps = true;
 }