bug#63411: [PATCH] pcomplete/systemctl cannot complete units for old versions of systemd

[Eli Zaretskii <eliz@gnu.org>]

> From: Liu Hui <liuhui1610@gmail.com>
> Date: Thu, 18 May 2023 21:29:46 +0800
> Cc: 63411@debbugs.gnu.org
> 
> > I'm not an expert on systemctl; would someone who uses that please
> > tell if this could have any downsides?  E.g., is --no-legend expected
> > to be deprecated, perhaps resulting in a warning message or something?
> > If not, why did the systemd developers add another option with the
> > same semantics?
> 
> --no-legend is indeed superseded by --legend=yes/no in systemd v248+,
> but it is not deprecated. It is kept for compatibility and is totally
> equivalent to --legend=no, and doesn't produce any warning message. I
> have tested with systemctl v249 on Ubuntu 22.04 and the outputs are
> same. In fact, the point of the new option is it allows to display
> legends by --legend=yes in spite of other options such as --quiet,
> which is explained in https://github.com/systemd/systemd/pull/18596.

Thanks, I think I will wait for a few days to let others chime in.

> Another simple solution is adding a variable, e.g.
> pcmpl-linux-systemd-list-unit-arguments, to allow users to change
> options passing to systemctl. WDYT?

If --no-legend will continue to be supported for the observable
future, asking users to control that would be an annoyance, I think.