bug#53590: 28.0.91; icompletion-vertical-mode gets stuck on 'M-x man RET awk'

[Eli Zaretskii]

> Date: Sat, 29 Jan 2022 19:10:14 +0000 (UTC)
> From: Van Ly <van.ly@sdf.org>
> cc: 53590@debbugs.gnu.org
> 
> >  man -k awk 2>/dev/null | cat
> >
> 
> The above fails as follows:
> 
> '''
> % man -k awk 2>/dev/null | cat
> zsh: segmentation fault  man -k awk 2> /dev/null |
> zsh: done                cat
> % echo $SHELL
> /usr/pkg/bin/zsh
> '''
> 
> Maybe the output redirect pipeline syntax for zsh is causing trouble.

Maybe.  Time for Unix shell gurus to chime in.  (And shouldn't
shell-file-name point to 'sh', not to your interactive shell?)  In any
case, this segfault seems to be a large part of the problem.