Hello all, As you probably have noticed, the Council has frozen the feature set for EAPI 4 in its November meeting [1], based on the current status of implementation in portage. These features include the REQUIRED_USE variable that will allow to specify constraints on USE flags possible for an ebuild, as proposed by ferringb [2].
A first wording for the REQUIRED_USE specification in PMS is available in bug 347353 [3]. As was pointed out in that bug, the current treatment of violated USE flag constraints isn't optimal. Portage basically would output "REQUIRED_USE violated", together with the variable's value and the package name. Such a message might not be very helpful for the user. And presumably there is no universal algorithm that can output a reasonable suggestion based on USE and REQUIRED_USE. Since generally the ebuild maintainer will know best what should be suggested to the user, a new function "pkg_required_use" has been proposed by zmedico. It would be triggered only in the case that REQUIRED_USE is not fulfilled, and it would output a message for the user, similar to pkg_nofetch for fetch-restricted packages. Comments? Ulrich [1] <http://www.gentoo.org/proj/en/council/meeting-logs/20101130.txt> <http://www.gentoo.org/proj/en/council/meeting-logs/20101130-summary.txt> [2] <http://archives.gentoo.org/gentoo-dev/msg_b0e868626019f497eba47194c34e5421.xml> [3] <http://bugs.gentoo.org/show_bug.cgi?id=347353>
