tulip: fix compilation by adding the `-fpermissive` flag

  qtWrapperArgs = [ ''--prefix PATH : ${lib.makeBinPath [ python3 ]}'' ];

  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.hostPlatform.isDarwin (toString [

  env.NIX_CFLAGS_COMPILE =

    # error: invalid conversion from 'unsigned char*' to 'char*'

    "-fpermissive "

    + (lib.optionalString stdenv.hostPlatform.isDarwin (toString [

      # fatal error: 'Python.h' file not found

      "-I${python3}/include/${python3.libPrefix}"

      # error: format string is not a string literal (potentially insecure)

      "-Wno-format-security"

  ]);

    ]));

  # FIXME: "make check" needs Docbook's DTD 4.4, among other things.

  doCheck = false;