Apply upstream fix for Nix on XFS

Fixes #6424.

pkgs/tools/package-management/nix/default.nix

@@ -12,6 +12,8 @@ stdenv.mkDerivation rec {
     sha256 = "a30a5e801bc1cb1019cbc3456d961a307c45c9c588b8692cf1293ea6588ef01c";
   };
 
+  patches = [ ./xfs.patch ];
+
   nativeBuildInputs = [ perl pkgconfig ];
 
   buildInputs = [ curl openssl sqlite ];

pkgs/tools/package-management/nix/xfs.patch

@@ -0,0 +1,13 @@
+diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
+index 119e71a..422ec97 100644
+--- a/src/libexpr/primops.cc
++++ b/src/libexpr/primops.cc
+@@ -796,7 +796,7 @@ static void prim_readDir(EvalState & state, const Pos & pos, Value * * args, Val
+     for (auto & ent : entries) {
+         Value * ent_val = state.allocAttr(v, state.symbols.create(ent.name));
+         if (ent.type == DT_UNKNOWN)
+-            ent.type = getFileType(path);
++            ent.type = getFileType(path + "/" + ent.name);
+         mkStringNoCopy(*ent_val,
+             ent.type == DT_REG ? "regular" :
+             ent.type == DT_DIR ? "directory" :