Bug#895134: libwx-scintilla-perl: needs tighter dependency on Wx build?

[Olly Betts]

On Sun, Apr 08, 2018 at 11:42:47AM +0300, Niko Tyni wrote:
> On Sat, Apr 07, 2018 at 09:57:15PM +0100, Olly Betts wrote:
> > On Sat, Apr 07, 2018 at 04:20:48PM +0300, Niko Tyni wrote:
> > > So to do this properly it looks like we need something to make
> > > sure the Perl Wx related packages are upgraded in sync. The
> > > virtual package provided by libalien-wxwidgets-perl (currently
> > > wxperl-gtk-3-0-4-uni-gcc-3-4) seems like a candidate, but I don't have
> > > a ready recipe for injecting that.
> > 
> > I'd guess that makes sense, but I don't entirely understand how the
> > libalien-wxwidgets-perl <-> libwx-perl connection works, or why we need
> > a chain of binNMUs after each new upstream wxwidgets3.0 release.
> 
> AIUI Alien::wxWidgets provides information about a wxwidgets installation,
> and libwx-perl uses that to offer machinery for building wxwidgets
> related Perl packages (the Wx::build namespace.)  This build machinery
> embeds the exact wxwidgets version/configuration from Alien::wxWidgets,
> and breaks if those get out of sync. Hence the binNMU requirement. See
> #757855 for the full story.

I've read that ticket already, but I'm not really clear on why it
requires the exact wxWidgets version.  If you built against wxWidgets
3.0.3.1 then the real requirement is $upstream_version >= 3.0.3.1 not
$upstream_version == 3.0.3.1 (or perhaps >= some lower version if there
were no ABI additions since that version).

Is there something more subtle here, or is this effectively an
Alien::wxWidgets upstream design flaw which it's hard for distros to
diverge from?

> Another approach would be to consider this a one time glitch (how often
> are we going to change toolkits anyway?), make libwx-perl Break older
> (gtk2 based) libwx-scintilla-perl and libwx-glcanvas-perl versions,
> and have those packages in turn depend on newer (gtk3 based) libwx-perl
> versions. That should handle it afaics.

If this is only because of the gtk2 to gtk3 switch, then this makes
sense to me.  It's the first time this will have happened since we've
had these two packages, and only the second time in 18 years we've
changed toolkit in the default wxwidgets packages (previously gtk1 to
gtk2).

I see that libwx-scintilla-perl has a BD on libalien-wxwidgets-perl
and seems to actually use it, but it looks like only for build flags
and similar.

Cheers,
    Olly