anchor.diff:    binutilsCross = forceBuildDrv (import ../development/tools/misc/binutils {
         inherit stdenv fetchurl;
         noSysDirs = true;
  -      cross = crossSystem;
  +      cross = assert crossSystem != null; crossSystem;
     });
   
     bison = bison23;
  
positive.code: 
    linuxHeadersCross = forceBuildDrv (import ../os-specific/linux/kernel-headers/2.6.32.nix {
      inherit stdenv fetchurl perl;
      cross = crossSystem;
    });
  
    linuxHeaders_2_6_18 = import ../os-specific/linux/kernel-headers/2.6.18.5.nix {
  
negative.code:     # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41818
      enableShared = if (crossSystem.arch == "sparc64") then false else true;
      crossStageStatic = false;
      cross = assert crossSystem != null; crossSystem;
    };
  
    gccCrossStageStatic = wrapGCCCross {
  