anchor.diff:      })
     ];
   
  +  postPatch = lib.optionalString withDocumentation ''
  +    patchShebangs doc/doxygen/gen-doxygen.py
  +  '';
  +
     outputs = [ "out" ] ++ lib.optionals withDocumentation [ "doc" "man" ];
     separateDebugInfo = true;
   
  
positive.code: # Documentation is only built when building libraries.
  assert withDocumentation -> withLibraries;
  
  # Require the optional to be enabled until upstream fixes or removes the configure flag
  assert expat != null;
  let
    isCross = stdenv.buildPlatform != stdenv.hostPlatform;
  in
  
negative.code:     "-Dlibraries=${lib.boolToString withLibraries}"
      "-Ddocumentation=${lib.boolToString withDocumentation}"
    ];
  
    depsBuildBuild = [
      pkg-config
  