Gentoo Archives: gentoo-dev

From: Ulrich Mueller <ulm@g.o>
To: gentoo-dev@l.g.o
Subject: [gentoo-dev] REQUIRED_USE in EAPI 4
Date: Wed, 08 Dec 2010 15:31:55
1 Hello all,
3 As you probably have noticed, the Council has frozen the feature set
4 for EAPI 4 in its November meeting [1], based on the current status of
5 implementation in portage. These features include the REQUIRED_USE
6 variable that will allow to specify constraints on USE flags possible
7 for an ebuild, as proposed by ferringb [2].
9 A first wording for the REQUIRED_USE specification in PMS is available
10 in bug 347353 [3]. As was pointed out in that bug, the current
11 treatment of violated USE flag constraints isn't optimal. Portage
12 basically would output "REQUIRED_USE violated", together with the
13 variable's value and the package name. Such a message might not be
14 very helpful for the user. And presumably there is no universal
15 algorithm that can output a reasonable suggestion based on USE and
18 Since generally the ebuild maintainer will know best what should be
19 suggested to the user, a new function "pkg_required_use" has been
20 proposed by zmedico. It would be triggered only in the case that
21 REQUIRED_USE is not fulfilled, and it would output a message for the
22 user, similar to pkg_nofetch for fetch-restricted packages.
26 Ulrich
28 [1] <>
29 <>
30 [2] <>
31 [3] <>