> It didn't help, unfortunately: I was indeed missing pyreadline, but
> installing it from conda repo made no difference :-(
> Neither did using "-i -u" as interactive Python arg.
>
> I vaguely remember this working with older Pythons -- what could
> probably change?

Hmm, can you try running the python code from
python-shell-completion-native-setup manually from a prompt and see what
comes out? (or where it goes wrong)