anchor.diff:  
   assert x11Support -> tcl != null
                     && tk != null
  -                  && xlibsWrapper != null
                     && libX11 != null;
   
   assert lib.assertMsg (enableOptimizations -> (!stdenv.cc.isClang))
  
positive.code: , openssl
  , readline
  , sqlite
  , tcl ? null, tk ? null, tix ? null, xlibsWrapper ? null, libX11 ? null, x11Support ? false
  , zlib
  , self
  , configd, coreutils
  
negative.code:     ++ optional (stdenv.hostPlatform.isCygwin || stdenv.hostPlatform.isAarch64) libffi
      ++ optional stdenv.hostPlatform.isCygwin expat
      ++ [ db gdbm ncurses sqlite readline ]
      ++ optionals x11Support [ tcl tk libX11 ]
      ++ optional (stdenv.isDarwin && configd != null) configd;
    nativeBuildInputs =
      [ autoreconfHook ]
  