anchor.diff:  
     smartdeblur = callPackage ../applications/graphics/smartdeblur { };
   
  -  snapper = callPackage ../tools/misc/snapper { };
  +  snapper = callPackage ../tools/misc/snapper {
  +    btrfs-progs = btrfs-progs_4_4_1;
  +  };
   
     snd = callPackage ../applications/audio/snd { };
   
  
positive.code:   bsod = callPackage ../misc/emulators/bsod { };
  
    btrfs-progs = callPackage ../tools/filesystems/btrfs-progs { };
  
    btrbk = callPackage ../tools/backup/btrbk { };
  
  
negative.code:   };
  
    docker = callPackage ../applications/virtualization/docker {
      btrfs-progs = btrfs-progs_4_4_1;
      go = go_1_4;
    };
  
  