anchor.diff:      (mkWith   (libaio != null)             "libaio"            null)
       (mkWith   (libxfs != null)             "libxfs"            null)
       (mkWith   (zfs != null)                "libzfs"            null)
  +  ] ++ optional (versionAtLeast version "10.0.0") [
  +    (mkWith   true                         "man-pages"         null)
  +    (mkWith   false                        "tcmalloc-minimal"  null)
  +    (mkWith   false                        "valgrind"          null)
     ];
   
     installFlags = [ "sysconfdir=\${out}/etc" ];
  
positive.code:     none = [ ];
    };
  
    wrapArgs = "--prefix PYTHONPATH : \"$(toPythonPath $lib)\""
      + " --prefix PYTHONPATH : \"$(toPythonPath ${python.modules.readline})\""
      + " --prefix PYTHONPATH : \"$(toPythonPath ${pythonPackages.flask})\""
      + " --prefix PATH : \"$out/bin\"";
  in
  stdenv.mkDerivation {
    name="ceph-${version}";
  
negative.code:   nativeBuildInputs = [ autoconf automake makeWrapper pkgconfig libtool which ];
    buildInputs = buildInputs ++ cryptoLibsMap.${cryptoStr} ++ [
      boost python libxml2 yasm libatomic_ops libs3 malloc pythonPackages.flask zlib
    ] ++ optional (versionAtLeast version "9.0.0") [
      git                   # Used for the gitversion string
      pythonPackages.sphinx # Used for docs
    ] ++ optional stdenv.isLinux [
  