Bug#1065726: dh_girepository: substvar doesn't handle dh_gencontrol overrides

[Jeremy Bícha]

Source: gobject-introspection
Version: 1.78.1-15

libgudev has a dh_gencontrol override to use an epoch in Ubuntu for
binary packages but not for the source package.

Things worked ok for libgudev 238-3 which was built on November 15,
2023 with 1.78.1-5.

However, when libgudev was rebuilt yesterday with
gobject-introspection 1.79.1-1, it now has these dependencies
(excerpt):

libgudev-1.0-dev
Depends: gir1.2-gudev-1.0 (= 238-3build1), gir1.2-gudev-1.0 (= 1:238-3build1)
Provides: gir1.2-gudev-1.0-dev (= 238-3build1)

The gir1.2-gudev-1.0 package is at version 1:238-3build1. This makes
libgudev-1.0-dev uninstallable. The first Depends is from gir:Depends.
The second is from an explicit gir1.2-gudev-1.0 (= ${binary:Version})
dependency (and it works).

I don't know offhand of any other Debian gir packages using epoch
overrides like this. We could bump libgudev's source package epoch in
Debian but there is usually resistance to that idea.

References
-----------
https://salsa.debian.org/gnome-team/libgudev/-/blob/debian/latest/debian/rules
https://launchpad.net/ubuntu/+source/libgudev/238-3/+latestbuild/amd64
https://launchpad.net/ubuntu/+source/libgudev/238-3build1/+latestbuild/amd64

Thank you,
Jeremy Bícha