anchor.diff:  
     preBuild = optionalString (kernel != null) ''
       ar vx SDEBS/*
  -    tar xf data.tar.gz
  +    tar xf data.tar.*
   
       cd usr/src/*
   
  
positive.code: 
    buildPhase = optionalString (kernel == null) ''
      ar vx DEBS/${name}*
      tar xf data.tar.gz
  
      rm usr/bin/mst
      mv etc/init.d/mst usr/bin
  
negative.code: }:
  
  let
    version = "4.11.0-103";
  
    urls' = arch: [
      "http://www.mellanox.com/downloads/MFT/mft-${version}-${arch}.tgz"
  