Re: [gentoo-dev] www-client/chromium gtk3 support

[Alexandre Rostovtsev]

On Wed, 2015-09-09 at 09:20 +0200, Paweł Hajdan, Jr. wrote:

In chromium's case (a new gtk3-based ui that needs wider testing), a
local gtk3 USE flag does make sense.

But in general, the gnome team recommends avoiding the gtk3 flag
whenever possible. We definitely don't want it to become a global flag.
We are trying to avoid the following scenario:

(1) Dozens of ebuilds add gtk3 USE flag, and the semantics of the gtk3
flag differ wildly in those ebuilds:
  (a) build an optional gui that happens to be based on gtk3 (instead
      of no gui at all);
  (b) build experimental gtk3-based gui (instead of stable gtk2 gui as
      recommended by upstream);
  (c) build recommended gtk3-based gui (instead of legacy gtk2-based
      gui which is not supported by upstream any more);
  (d) build widget library and utilities for gtk3 (possibly in parallel
      with gtk2 widgets and utilities);
  (e) build widget library and utilities for gtk3 (and disable gtk2
      widgets and utilities - without making any effort to allow both
      gtk2 and gtk3 support in parallel by splitting the package or
      renaming a few files).
(3) Since the flag is used all over the place, some users try to
globally enable or disable it, depending on their personal feelings
about Adwaita's tab shapes.
(4) Since the flag sometimes means "build a gui (instead of no gui at
all)" at some point it gets globally enabled in some profile.
(5) Users are forced to maintain giant lists of package.use entries to
get a usable desktop environment. Unhappiness reigns.

In other words, to avoid the scenario that happened during gtk1/gtk2
transition, and which is now starting with qt4/qt5 [1].

[1] https://archives.gentoo.org/gentoo-dev/message/11e3d077e0d9c953597c3d17f327c6b3