Revert "nix: revert overlay changes and add conditionals to derivation for flake build"

packages/nix/polymc/default.nix

@@ -15,10 +15,9 @@
 , qtbase
 , libGL
 # submodules
-, isFlakeBuild ? false
-, self ? ""
-, submoduleNbt ? ""
-, submoduleQuazip ? ""
+, self
+, submoduleNbt
+, submoduleQuazip
 }:
 
 let
@@ -35,26 +34,19 @@ in
 
 mkDerivation rec {
   pname = "polymc";
-  version = if isFlakeBuild then "nightly" else "1.0.4";
+  version = "nightly";
 
-  src = if isFlakeBuild then lib.cleanSource self
-    else fetchFromGitHub {
-    owner = "PolyMC";
-    repo = "PolyMC";
-    rev = "${version}";
-    sha256 = "sha256-8aya0KfV9F+i2qBpweWcR9hwyTSQkqn2wHdtkCEeNvk=";
-    fetchSubmodules = true;
-  };
+  src = lib.cleanSource self;
 
   nativeBuildInputs = [ cmake file makeWrapper ];
   buildInputs = [ qtbase jdk8 zlib ];
 
-  postUnpack = if isFlakeBuild then ''
+  postUnpack = ''
     mkdir source/libraries/{libnbtplusplus,quazip}
     cp -a ${submoduleNbt}/* source/libraries/libnbtplusplus
     cp -a ${submoduleQuazip}/* source/libraries/quazip
     chmod a+r+w source/libraries/{libnbtplusplus,quazip}/*
-  '' else "";
+  '';
 
   cmakeFlags = [
     "-DLauncher_LAYOUT=lin-system"