anchor.diff:        bunzip2 < ${packagesList} > ./Packages
   
         # Work around this bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=452279
  -      substituteInPlace ./Packages --replace x86_64-linux-gnu x86-64-linux-gnu
  +      sed -i ./Packages -e s/x86_64-linux-gnu/x86-64-linux-gnu/g
   
         ${perl}/bin/perl -I${dpkg} -w ${deb/deb-closure.pl} \
           ./Packages ${urlPrefix} ${toString packages} > $out
  
positive.code:     QEMU_OPTS = "-m ${toString (if attrs ? memSize then attrs.memSize else 256)}";
    });
  
    extractFs = {file, fs ? null} :
      with pkgs; runInLinuxVM (
      stdenv.mkDerivation {
  
negative.code:       '';
      });
  
      
    qemuCommandGeneric = ''
      ${kvm}/bin/qemu-system-x86_64 \
        -nographic -no-reboot \
  