bundix: add final newline patch

pkgs/development/ruby-modules/bundix/default.nix

@@ -1,5 +1,5 @@
 { buildRubyGem, fetchFromGitHub, makeWrapper, lib, bundler, nix,
-  nix-prefetch-git }:
+  nix-prefetch-git, fetchpatch }:
 
 buildRubyGem rec {
   inherit (bundler) ruby;
@@ -15,6 +15,15 @@ buildRubyGem rec {
     sha256 = "05y8sy6v9km1dwvpjzkjxpfzv95g6yzac1b5blac2f1r2kw167p8";
   };
 
+  patches = [
+    # write trailing newline to gemset.nix
+    # https://github.com/nix-community/bundix/pull/78
+    (fetchpatch {
+      url = "https://github.com/nix-community/bundix/commit/02ca7a6c656a1e5e5465ad78b31040d82ae1a7e6.patch";
+      sha256 = "18r30icv7r79dlmxz1d1qlk5b6c7r257x23sqav55yhfail9hqrb";
+    })
+  ];
+
   buildInputs = [ ruby bundler ];
   nativeBuildInputs = [ makeWrapper ];