anchor.diff:    ];
   
     buildInputs = [
  -    boost_1-66
  +    boost'
       curl
       expat
       fuse_2
  
positive.code:     postPatch = ''
        grep -q 'locations = (' ceph_volume/util/system.py
        sed -i "/locations = (/a\        '/run/current-system/sw/bin'," ceph_volume/util/system.py
      '';
    };
  in
  
negative.code: 
  let
    inherit (stdenv.lib)
      concatMapStrings
      head
      replaceChars;
  
    sources = (import ./sources.nix)."${channel}";
  