Default value of VALA_MAX_API_VERSION should be updated to "0.24".
Not until it is unmasked or some package outside of the Gnome 3.12 mask needs it.
vala-0.24 was already unmasked :) I would suggest that now, while 3.12 is still masked, is the best time to test whether setting VALA_MAX_API_VERSION to 0.24 breaks anything in gnome-3.10 or external applications (e.g. shotwell), adjust the ebuilds that don't work with 0.24, and then change the eclass.
Note that it will break ebuilds like anjuta. See bug #508706.
(In reply to Gilles Dartiguelongue from comment #4) > Note that it will break ebuilds like anjuta. See bug #508706. I don't fully understand you comment in that bug report, isn't enough with setting MAX version to the MIN one in ebuild as we were doing until now? :/
I rebuilt everything that uses vala.eclass and saw only 4 packages (gnome-contacts, activity-log-manager, systemd-ui and uevt) that don't work with valac-0.24; these now have VALA_MAX_API_VERSION=0.22. So vala.eclass should now be safe to update.
+ 04 May 2014; Alexandre Rostovtsev <tetromino@gentoo.org> vala.eclass: + Update VALA_MAX_API_VERSION (bug #509222, thanks to Arfrever) and modernize + VALA_MIN_API_VERSION too.