anchor.diff:  
   rec {
   
  -  qemu = pkgs.qemu_kvm;
  +  qemu = buildPackages.qemu_kvm;
   
     modulesClosure = makeModulesClosure {
       inherit kernel rootModules;
  
positive.code:   debClosureGenerator =
      {name, packagesLists, urlPrefix, packages}:
  
      runCommand "${name}.nix" { buildInputs = [ perl dpkg ]; } ''
        for i in ${toString packagesLists}; do
          echo "adding $i..."
          case $i in
  
negative.code:   hd = "vda"; # either "sda" or "vda"
  
    initrdUtils = runCommand "initrd-utils"
      { nativeBuildInputs = [ buildPackages.nukeReferences ];
        allowedReferences = [ "out" modulesClosure ]; # prevent accidents like glibc being included in the initrd
      }
      ''
  