I actually see similar messages when running retext via the python debugger,
but in my case the app just keeps going. So, this may not be the major issue.
Fwiw, you can run gdb on the coredump process as follows:
sudo coredumpctl list # List all coredumps
sudo coredumpctl gdb <pid> # Where <pid> is the process-id from
# the above list which dumped core
May be this helps.