anchor.diff:  
     inherit (sources)
       version;
  +
  +  src = fetchurl {
  +    url = "https://github.com/wkennington/ceph/releases/download/${version}/ceph-${version}.tar.xz";
  +    inherit (sources) sha256;
  +  };
  +
  +  cephDisk = python3Packages.buildPythonPackage {
  +    name = "ceph-disk-${version}";
  +
  +    inherit src;
  +
  +    prePatch = ''
  +      cd src/ceph-disk
  +    '';
  +  };
  +
  +  cephVolume = python3Packages.buildPythonPackage {
  +    name = "ceph-volume-${version}";
  +
  +    inherit src;
  +
  +    prePatch = ''
  +      cd src/ceph-volume
  +    '';
  +  };
   in
   stdenv.mkDerivation rec {
     name = "ceph-${version}";
   
  -  src = fetchurl {
  -    url = "https://github.com/wkennington/ceph/releases/download/${version}/${name}.tar.xz";
  -    inherit (sources) sha256;
  -  };
  +  inherit src;
   
     nativeBuildInputs = [
       cmake
  
positive.code: 
    # FIXME
    buildDirCheck = false;
  
    meta = with stdenv.lib; {
      maintainers = with maintainers; [
  
negative.code:     # Bring in lib as a native build input
      mkdir -p "$out"/nix-support
      echo "$lib" > "$out"/nix-support/propagated-native-build-inputs
  
      ln -sv "${cephDisk}/bin/ceph-disk" "$out"/bin
      ln -sv "${cephVolume}/bin/ceph-volume" "$out"/bin
    '';
  
    preFixup = ''
  