Re: [gentoo-user] Is Gentoo wiping out Gtk 2 support from packages that support it?

[Alan McKinnon <alan.mckinnon@gmail.com>]

On Friday 08 July 2011 18:39:04 Stroller did opine thusly:
> On 8 July 2011, at 16:19, Alan McKinnon wrote:
> > ...
> > easy.
> > 
> > Two USE flags: gtk2 and gtk3
> > 
> > in ebuild:
> > 
> > DEPEND="
> > 
> >    gtk2? (x11-libs/gtk+:2)
> >    gtk3? (x11-libs/gtk+:3)
> > 
> > "
> > 
> > in src-configure() write the code such that it establishes a
> > precedence
> > 
> > If both flags are set, build against gtk+:3
> > If only one flag is set, build against that toolkit
> > If no flags are set, do something appropriate.
> 
> This is the way it was done for gtk vs. gtk2, but the bug has been
> updated since I first read it (over 24 hours ago) and apparently
> the Gnome team don't want the two separate flags in the future.
> 
> I'm not really a gtk or Gnome (or X11) user, so I don't really know,
> but the two separate flags did strike me as a bit of an ugly /
> clumsy way of doing things.

It's also the only mechanism I know of to do it.

If the ebuild will support two toolkits and the choice of which to use 
is based solely on a user's preference, there is only one way to 
resolve that - a precedence list. There's no way around that.

Some global mechanism would be nice and could be useful in various 
cases:

gtk+-2 vs gtk+-3
openssl vs gnuts
mysql vs mariadb

Those are also virtuals.


-- 
alan dot mckinnon at gmail dot com