> So I'm failing to find any documentation for libedit, but it looks as
> though this error occurs if rl_read_init_file fails to find an
> .editrc file in the appropriate place.  If I create an empty .editrc
> file in my home directory, the error disappears.  (Having an
> .inputrc file doesn't seem to make a difference either way.)
> 
> Perhaps the solution is to ignore an OSError from
> readline.read_init_file in register_readline---i.e., add a try /
> except OSError there.

This sounds fine to me. Can you propose a patch? I'm unlikely to ever have
an OS X machine.