gnuradio error

I installed gnuradio on  Fedora  5.4.17-200.fc31.x86_64 using sudo dnf install gnuradio

Afterwards when I attempt to run gnuradio-companion (typing gnuradio-companion in a terminal) I see several errors at start up

Warning: restarting the docstring loader (crashed while loading 'qtgui_bercurve_sink')
Warning: restarting the docstring loader (crashed while loading 'qtgui_const_sink_x')
Warning: restarting the docstring loader (crashed while loading 'qtgui_edit_box_msg')
Warning: restarting the docstring loader (crashed while loading 'qtgui_freq_sink_x')
Warning: restarting the docstring loader (crashed while loading 'qtgui_histogram_sink_x')
Warning: docstring loader crashed too often

The gnuradio GUI opens up but using QT widgets causes a seg fault.

Any help appreciated.

Mike