[Debian-astro-maintainers] Bug#1005725: gavodachs2-server: fails to install with new python3-twisted.

[Markus Demleitner]

On Sun, Feb 13, 2022 at 11:57:56PM +0000, peter green wrote:
> > Exception payload: module 'twisted.web.template' has no attribute
> > '_ToStan'
> > dpkg: error processing package gavodachs2-server (--configure):
> >  installed gavodachs2-server package post-installation script subprocess returned error exit status 1
> 
> I attempted to fix that error (debdiff attatched), however it then
> failed with a "TypeError: 'Tag' object is not subscriptable", I
> modified the error handling to get a backtrace, but it didn't leave
> me any the wiser as to what the actual problem was.

The problem is a good deal deeper -- DaCHS needs some functionality
in the stan templates previously provided by nevow.  To have that, it
needs to patch template.Tag (and yes, someone should try to get
twisted.web have a configurable Tag class); that, however, has
changed its interface in subtle ways (and needs to be monkeypatched
in other places).

I *think* the patch at https://docs.g-vo.org/twisted-21-patch.txt
ought to do the trick, but since the postgres in my unstable
container keeps crashing on me right now, it's not properly tested
yet.

My plan right now would be to fix this in unstable by just packaging
release 2.6, which ought to happen in May 2022 and will contain the
patch (or whatever else).  If that's a major problem for someone,
speak up and I'll try to provide a more timely fix.

         -- Markus