nix: fix overlay

flake.nix

@@ -26,9 +26,9 @@
           };
         };
 
-        overlay = import ./packages/nix/overlay.nix {
-          inherit self quazip libnbtplusplus;
-        };
+        overlay = (final: prev: rec { 
+          polymc = packages.polymc;
+        });
 
         apps = {
           polymc = flake-utils.lib.mkApp {

packages/nix/overlay.nix

@@ -1,9 +0,0 @@
-{ self, quazip, libnbtplusplus }:
-
-final: prev: rec {
-  polymc = prev.libsForQt5.callPackage ./polymc {
-    inherit self;
-    submoduleQuazip = quazip;
-    submoduleNbt = libnbtplusplus;
-  };
-}

packages/nix/polymc/default.nix

@@ -42,6 +42,7 @@ mkDerivation rec {
   buildInputs = [ qtbase jdk8 zlib ];
 
   postUnpack = ''
+    rm -rf source/libraries/{libnbtplusplus,quazip}
     mkdir source/libraries/{libnbtplusplus,quazip}
     cp -a ${submoduleNbt}/* source/libraries/libnbtplusplus
     cp -a ${submoduleQuazip}/* source/libraries/quazip