[Freewx-maint] wxWidgets 3.x and GTK+ 3

[Olly Betts]

Björn Harrtell <bjorn.harrtell at gmail.com> wrote:
> I'm wondering if there are any plans to package wxWidgets 3.0/3.1
> compiled for GTK+ 3?

It's not feasible to package wxWidgets 3.1, as it doesn't have a stable
ABI - each new upstream version would potentially require a library
transition in Debian.

I had been hoping to switch to GTK3 with wx 3.2, but currently it looks
unlikely to me that upstream will release 3.2 soon, or at least soon
enough for it to be feasible to switch to for buster (we probably have
about 16 months before the buster freeze.  The 2.8 to 3.0 transition
took around a year, though there were quite a lot of incompatibilities
to deal with - I'd hope 3.0 to 3.2 is smoother, but even so with the
number of reverse dependencies wx has in Debian, a transition will take
time).

History has shown we also don't really have the resources to maintain two
versions of wxWidgets in parallel (whenever we've had multiple versions
packaged, all but one has essentially been left to rot).  So it would
really need a complete switch to wx 3.0 using GTK3 for buster.

> Is there anything I can do to help?

The first thing we need to determine is whether the GTK version used
affects the ABI of the built libraries, so that would be useful to
check.  To do that, grab the package source from the git repo (best
to use that as it has 3.0.3.1), and build it, then modify it to use
GTK3 and build again.  Compare the two outputs with an ABI comparison
tool (e.g. abi-compliance-checker).

If they're not ABI compatible, this will need a library transition and
coordination with the release team.

Either way, it's also likely to need a significant amount of fielding of
bug reports as the maintainers and users of the rdeps find problems
due to the switch.  These will need analysing to decide if they're specific
to Debian or not, and if not if there's already a fix upstream we can
cherry pick, or if there's already an open bug upstream, or if it needs a
new upstream bug report.  So help with all that would be very useful.

Cheers,
    Olly