Re: [gentoo-portage-dev] Try to specify how to get that a USE flag is present in current ebuild

[Zac Medico]

On 09/21/2012 01:38 PM, Brian Harring wrote:
> On Fri, Sep 21, 2012 at 12:45:30PM -0700, Zac Medico wrote:
>> On 09/21/2012 12:08 PM, Pacho Ramos wrote:
>>> Hello
>>>
>>> This comes from this gentoo-dev thread:
>>> http://www.gossamer-threads.com/lists/gentoo/dev/260536
>>>
>>> In that one, we try to use the following:
>>> has vala ${IUSE//+/} && ! use vala && return 0
>>>
>>> as already done in many eclasses/ebuilds. The problem is that Ciaran
>>> wants to forbid it because he says it's not specified in PMS. My
>>> suggestion was to simply specify it as it's currently implemented in
>>> portage because that functionality is (apart of needed) being used for a
>>> long time in the tree by numerous eclasses/ebuilds, then, from my point
>>> of view, wouldn't be any sense on lose time for moving them to current
>>> functionality to a worse one, wait for the next eapi and, finally,
>>> revert them back to current behavior.
>>>
>>> The problem is that I cannot find any doc about how this is currently
>>> handled in portage. Could you help me on it please?
>>
>> That `has vala ${IUSE//+/}` thing should work for all versions of
>
> *cough* negated defaults; you need a - in addition.

Good point. The negated ones didn't have much meaning for a long time,
so it's easy to overlook them. Nowadays, they can be used to negate
repo-level defaults [1].

[1] https://bugs.gentoo.org/show_bug.cgi?id=370693
-- 
Thanks,
Zac