anchor.diff:      QEMU_OPTS = "-m ${toString (if attrs ? memSize then attrs.memSize else 256)}";
     });
   
  +  
     extractFs = {file, fs ? null} :
       with pkgs; runInLinuxVM (
       stdenv.mkDerivation {
  
positive.code:       '';
      });
  
    qemuCommandGeneric = ''
      ${kvm}/bin/qemu-system-x86_64 \
        -nographic -no-reboot \
  
negative.code:       '';
      });
  
      
    extractMTDfs = {file, fs ? null} :
      with pkgs; runInLinuxVM (
      stdenv.mkDerivation {
  