anchor.diff:        --replace "'/bin/sh'" "'${bash}/bin/sh'"
     '' + optionalString mimetypesSupport ''
       substituteInPlace Lib/mimetypes.py \
  -      --replace "@mime-types@" "${mime-types}"
  +      --replace "@mime-types@" "${mailcap}"
     '' + optionalString (x11Support && (tix != null)) ''
       substituteInPlace "Lib/tkinter/tix.py" --replace "os.environ.get('TIX_LIBRARY')" "os.environ.get('TIX_LIBRARY') or '${tix}/lib'"
     '';
  
positive.code:                   && libX11 != null;
  
  assert bluezSupport -> bluez != null;
  
  assert mimetypesSupport -> mime-types != null;
  
  assert lib.assertMsg (enableOptimizations -> (!stdenv.cc.isClang))
    "Optimizations with clang are not supported. configure: error: llvm-profdata is required for a --enable-optimizations build but could not be found.";
  
negative.code: , libffi
  , gdbm
  , xz
  , mailcap, mimetypesSupport ? true
  , ncurses
  , openssl
  , readline
  