anchor.diff:    jhiccup = callPackage ../development/tools/java/jhiccup { };
   
     valgrind = callPackage ../development/tools/analysis/valgrind {
  -    inherit (darwin) xnu bootstrap_cmds cctools;
  +    inherit (buildPackages.darwin) xnu bootstrap_cmds cctools;
       llvm = llvm_39;
     };
     valgrind-light = self.valgrind.override { gdb = null; };
  
positive.code:   };
  
    ccl = callPackage ../development/compilers/ccl {
      inherit (darwin) bootstrap_cmds;
    };
  
    chez = callPackage ../development/compilers/chez {
  
negative.code:   xorg = recurseIntoAttrs ((lib.callPackageWith __splicedPackages ../servers/x11/xorg {
    }).overrideScope' (lib.callPackageWith __splicedPackages ../servers/x11/xorg/overrides.nix {
      inherit (darwin) apple_sdk;
      bootstrap_cmds = if stdenv.isDarwin then buildPackages.darwin.bootstrap_cmds else null;
      python = python2; # Incompatible with Python 3x
      udev = if stdenv.isLinux then udev else null;
      libdrm = if stdenv.isLinux then libdrm else null;
  