On Thu, 17 Aug 2023, 20:57 Nicholas D Steeves, <s...@debian.org> wrote:
> Richard Lewis wrote:
> > David Bremner wrote:
> > > Richard Lewis writes:
> > > > David Bremner wrote:
>
>
> > What happens in the 'apt upgrade' is:
> >
> > the old emacsen-common prerm is called ('<old prerm> upgrade
> > <new-version>'):
>
> and at the end it _unlinks_:
> > /var/lib/emacsen-common/state/package/installed/emacsen-common
>
> @1
>
> > Then, apt prepares to unpack elpa-dash:
> >
> > The elpa-dash prerm (from bullseye) is called as:
> > /var/lib/dpkg/info/elpa-dash.prerm upgrade
> > 2.19.1+git20220608.1.0ac1ecf+dfsg-1)
> >
> > but this starts with:
> >
> > if [ -e /var/lib/emacsen-common/state/package/installed/emacsen-common -a
> > -x
> > /usr/lib/emacsen-common/emacs-package-remove ] ; then
> > /usr/lib/emacsen-common/emacs-package-remove --prerm elpa-dash
> >
> > fi
> >
> > ... and so does nothing,
> > because /var/lib/emacsen-common/state/package/installed/emacsen-common is
> > gone.
>
> Oh! It's a state-related bug! I wonder if emacsen-common (old version)
> has been deinstalled at @1 (see above), or if the state is
> emacsen-common (new version) is unpacked, but unconfigured, and thus
> missing /var/lib/emacsen-common/state/package/installed/emacsen-common,
> which is presumably created as a last step during package configuration
> post-unpack?
>
the latter - new emacsen-common is present but in state 'unpacked' before
new dh-* is unpackaged
> In other words, elpa-dash (and other...most?..all? dh-elpa-using
> packages) upgrades depends on having emacsen-common fully installed and
> configured at @1.
>
this is my understanding yes: this is a feature/assumption made by the
current design but not enforced through package dependencies or code in apt
> I wonder if this can be solved in emacsen-common, or if it needs to be
> solved in dh-elpa and then all the dh-elpa-using packages rebuilt to
> generate new prerm scripts? Which do you think would be the better
> approach?
>
I would guess the former is possible. but I think what is missing is clear
documentation of what features all the machinery with emacsen-common and
'flavors' and dh-elpa is trying to provide
( i suspect dpkg triggers should be the answer- should the question be
understood better --- eg it looks like jed does something similar with .sl
files, at least i think it does -- i didnt find any documentation on that
either)
