Bug#1060907: haskell-haskell-gi: Please search the same paths for GIR XML that GObject-Introspection does

[Simon McVittie]

Source: haskell-haskell-gi
Version: 0.26.7-2
Severity: normal
Tags: trixie sid
User: pkg-gnome-maintainers at lists.alioth.debian.org
Usertags: gi-gir-path

The gobject-introspection package had a long-standing bug that
GLib-2.0.gir was installed in /usr/share, but has architecture-dependent
contents, preventing it from being co-installed on different
architectures. Recent versions solve this by moving GLib-2.0.gir
to /usr/lib/${DEB_HOST_MULTIARCH}/gir-1.0 (in the gir1.2-glib-2.0-dev
package), and configuring gobject-introspection to search that path.

Unfortunately, various other packages like haskell-haskell-gi also
want to read GIR XML, and they don't search the same directories
for it that gobject-introspection does. For backwards compatibility,
gobject-introspection still installs a symbolic link
/usr/share/gir-1.0/GLib-2.0.gir -> ../../lib/${DEB_HOST_MULTIARCH}/GLib-2.0.gir
in the libgirepository1.0-dev package to avoid breaking those tools,
but I would prefer that symlink to disappear eventually.

There is at least one other package that has an architecture-dependent
GIR XML file: GstAudio-1.0.gir in libgstreamer-plugins-base1.0-dev
(https://bugs.debian.org/1016631). Having a symbolic link in /usr/share
is probably not an option here, because there's no convenient package
split to take advantage of; but if we move GstAudio-1.0.gir into
/usr/lib/${DEB_HOST_MULTIARCH}, then haskell-haskell-gi will become
unable to process it.

I think the best way to solve this in haskell-haskell-gi
would be to propose changes upstream to make it use
the same search path as gobject-introspection, similar to
e.g. https://gitlab.gnome.org/GNOME/vala/-/issues/1518 in Vala,
and then apply those changes in Debian (as a backported patch if
necessary) and configure it in a suitable way so that it searches
/usr/lib/${DEB_HOST_MULTIARCH}. Sorry, I don't know Haskell, so I am
unable to propose a concrete solution for this.

If that cannot be done in the near future, a less good alternative
would be to have a Debian-specific patch hard-coding it to search
/usr/lib/${DEB_HOST_MULTIARCH}. Again, I don't know Haskell, so I am
unable to propose a patch.

Thanks,
    smcv