fix evaluation on darwin, fixing tarball job fully

pkgs/development/compilers/llvm/3.4/llvm.nix

@@ -46,7 +46,7 @@ in stdenv.mkDerivation rec {
     "-DLLVM_BUILD_TESTS=ON"
     "-DLLVM_ENABLE_FFI=ON"
     "-DLLVM_REQUIRES_RTTI=1"
-    "-DLLVM_BINUTILS_INCDIR=${binutils.dev}/include"
+    "-DLLVM_BINUTILS_INCDIR=${binutils.dev or binutils}/include"
     "-DCMAKE_CXX_FLAGS=-std=c++11"
   ] ++ stdenv.lib.optional (!isDarwin) "-DBUILD_SHARED_LIBS=ON";
 

pkgs/os-specific/linux/xf86-input-multitouch/default.nix

@@ -10,6 +10,8 @@
 , libpciaccess
 }:
 
+assert stdenv.isLinux;
+
 stdenv.mkDerivation {
   name = "xf86-input-multitouch-20110312";