PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> If you run
> SELECT '' ~ '(?:[^\d\D]){0}';
> it will assert with "lp->nouts == 0 && rp->nins == 0"
> This behavior have been introduced in 2a0af7fe460 commit.
Thanks for the report --- I'll dig into this later.
regards, tom lane