Re: [gentoo-user] Re: Portage option "--changed-use" not working?

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

On Fri, 20 Jan 2012 11:00:52 -0600
»Q« <boxcars@gmx.net> wrote:

> On Fri, 20 Jan 2012 12:06:22 +0000
> Neil Bothwick <neil@digimed.co.uk> wrote:
> 
> > I suspect this is
> > specific to the KDE ebuilds (or eclass). changed-use should only
> > skip an ebuild with changed flags if re-emerging would produce
> > exactly the same code as before, this may not be the case. For
> > example, in some ebuilds, it is the absence of a USE flag that
> > triggers an extra configure option, so removing that use flag would
> > give the same code as if the package had been emerged with it
> > enabled.
> > 
> > Something like this happened recently with the nls flag on glibc.
> 
> Ah, that makes sense -- thanks.  (And now I wish I'd read the entire
> thread in dev before I posted a few minutes ago.)
> 
> IMO, the man page's section on --changed-use should say what you've
> just said rather than what it says now.

I saw the logs from the kde team meeting where they discussed removing
kdeenablefinal and decided when to do it. My own update on that ran
overnight so I wasn't too fazed.

But is this not a case where the kde eclass *explictly* set the USE
flag off? (Disclaimer: haven't read the eclass). In that case portage
would not know what to do when the flag goes away so the behaviour we
saw would not really be a bug, it would be "playing safe"

--changed-use is intended for cases like a flag you are not using at
all goes away. Caveat: Even then it could still break in subtle ways
with dodgy ebuilds. Caveat emptor.


 
-- 
Alan McKinnnon
alan.mckinnon@gmail.com