[gentoo-dev] Re: RFD: new global USE flag gtk3

[Ryan Hill]

On Thu, 20 Feb 2014 05:16:55 -0500
Alexandre Rostovtsev <tetromino@g.o> wrote:

> The other unfortunate aspect of the gtk3 flag is that it encourages
> using flags instead of slotting for libraries that can support both gtk
> and gtk3, resulting in needless rebuilds of when one of the flags is
> switched on/off. But again, that could be addressed with a bit of
> documentation.

Slotting a library by toolkit rather than by version just doesn't work in a lot
of cases.  Having multiple versions of a library installed is common enough
practice and upstreams will often take that into account and version their
library names, include paths, pkgconfig files, etc.  Most don't do that for
different toolkits.  So if you're slotting by toolkit you have to start
installing one in a non-standard location to prevent file collisions (and it's
always the newer toolkit since you don't want to break existing packages), and
every new ebuild using that toolkit needs to be changed to look in the right
place, and you have to start futzing around with symlinks, and wrapper scripts,
and eselect, and eclasses, and every time some dev uses the wrong depend atom
you get a bug about it, and it goes on and on and on.

Or you can add USE=gtk3, deal with collisions internally, install one set of
headers, and go do something productive with your life.

wxGTK not only splits up libraries by version and toolkit, but also by charset
and debug/release.  If we had to use different SLOTs rather than USE flags we
would need eight of them for 2.8 alone.  And I don't know how we would name the
ebuilds (-r100,-r200,... ugh).


-- 
Ryan Hill                        psn: dirtyepic_sk
   gcc-porting/toolchain/wxwidgets @ gentoo.org

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