ats-acc: fix build

pkgs/development/compilers/ats2/default.nix

@@ -34,6 +34,10 @@ stdenv.mkDerivation rec {
     hash = "sha256-UWgDjFojPBYgykrCrJyYvVWY+Gc5d4aRGjTWjc528AM=";
   };
 
+  postPatch = lib.optionalString stdenv.cc.isClang ''
+    sed -i 's/gcc/clang/g' utils/*/DATS/atscc_util.dats
+  '';
+
   buildInputs = [ gmp ];
 
   # Disable parallel build, errors:

pkgs/development/tools/ats-acc/default.nix

@@ -11,6 +11,11 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-Wp39488YNL40GKp4KaJwhi75PsYP+gMtrZqAvs4Q/sw=";
   };
 
+  postPatch = ''
+    substituteInPlace Makefile \
+      --replace "mv acc \''$(PATSHOME)/bin/" "install -Dm755 acc ${placeholder "out"}/bin/"
+  '';
+
   nativeBuildInputs = [ ats2 ];
 
   meta = with lib; {