[Freewx-maint] Start building GTK+3 packages

[Olly Betts]

On Sun, Mar 04, 2018 at 10:20:42PM -0500, Scott Talbert wrote:
> My hope would be that we could have only wx3.0 with GTK3 in buster. However,
> if we have to keep wx3.0 with GTK2 as well, I don't think that would be the
> end of the world.  Even though upstream seems to be moving closer to a
> release, I think there's too much uncertainty with wx3.2 to try to make any
> plans based on it.
> 
> So, thus I think the recommendation would be: use wx3.0 GTK3 unless it
> causes problems for your app.  And if we can get all of the users, off GTK2,
> great, then we can remove it.

OK, so once this is in place, we should start to gently nudge
maintainers towards it, then review progress nearer buster.

Are you thinking to just provide wxpython built against the GTK3
variant?

> >I don't currently have a salsa login set up so can't directly comment
> >on the patch, but not sure why you configure GTK3 with:
> >
> >>+    --cache-file=/dev/null \
> 
> Hmm, I thought they created accounts for all DD's.  It does look like you
> have an account: https://salsa.debian.org/olly

But I don't have a password for it, so it's not usefully "set up" yet.
I've not have a chance to read the salsa docs yet - perhaps I just need
to do a password reset.

> I had to do that in order to get configure to correctly detect GTK+3.
> Otherwise, it found and used the cached version of GTK+2 from the previous
> configure run.  If you can think of a better way to deal with that problem,
> let me know.

Oh I see what's happening:

config_cache       = ../config_deb.cache

and:

COMMON_CONFIGURE_OPTIONS := \
    --prefix=/usr \
    --cache-file=$(config_cache) \

I guess the idea is to put the cache where it's not removed by
"debian/rules clean" so that when testing stuff outside of a chroot
builder you get a faster rerun of configure.

If that's actually a useful gain, perhaps it's worth having a
"config_cache_gtk3" or something.  Or we could just scrap passing
--cache-file at all and simplify debian/rules.  Using ccache provides a
speed-up to configure that probably isn't quite as good but persists
between runs better and can benefit chroot builds with a suitable setup.

I don't know what others do, but since we split out wxpython the build
time for wxwidgets packages with a modern machine in a chroot is short
enough that I've not personally felt the need to fiddle around outside
one.

Anyway, overriding it to /dev/null for GTK3 seems OK if we actually
understand why it's needed - I was just concerned that the need to do so
indicated a deeper problem somewhere.

Cheers
    Olly