Merge pull request #19470 from copumpkin/fix-sierra

Fix Darwin stdenv to work on Sierra

pkgs/development/compilers/llvm/3.7/llvm.nix

@@ -35,6 +35,18 @@ in stdenv.mkDerivation rec {
 
   propagatedBuildInputs = [ ncurses zlib ];
 
+  # The goal here is to disable LLVM bindings (currently go and ocaml) regardless
+  # of whether the impure CMake search sheananigans find the compilers in global
+  # paths. This mostly exists because sandbox builds don't work very well on Darwin
+  # and sometimes you get weird behavior if CMake finds go in your system path.
+  # This would be far prettier if there were a CMake option to just disable bindings
+  # but from what I can tell, there isn't such a thing. The file in question only
+  # contains `if(WIN32)` conditions to check whether to disable bindings, so making
+  # those always succeed has the net effect of disabling all bindings.
+  prePatch = ''
+    substituteInPlace cmake/config-ix.cmake --replace "if(WIN32)" "if(1)"
+  '';
+
   # hacky fix: created binaries need to be run before installation
   preBuild = ''
     mkdir -p $out/