[Mageia-dev] Problem with gdm metacity again

Wed Sep 7 14:27:05 CEST 2011

'Twas brillig, and JA Magallon at 07/09/11 12:03 did gyre and gimble:
+> On Wed, 7 Sep 2011 13:01:39 +0300
+> Shlomi Fish <shlomif at shlomifish.org> wrote:
+> 
+>> Hi J. A.,
+>>
+>> On Wed, 7 Sep 2011 11:42:33 +0200
+>> JA Magallon <jamagallon at ono.com> wrote:
+>>
+>>> On Wed, 7 Sep 2011 11:15:21 +0200
+>>> JA Magallon <jamagallon at ono.com> wrote:
+>>>
+>>>> Hi...
+>>>>
+>>>> This old problem has surfaced again:
+>>>>
+>>>> .xsession-errors:
+>>>>
+>>>> ...
+>>>> Window manager warning: Screen 0 on display ":0" already has a window manager; try using the --replace option to replace the current window manager.
+>>>> Window manager warning: Screen 0 on display ":0" already has a window manager; try using the --replace option to replace the current window manager.
+>>>> ...
+>>>>
+>>>> I get only the nautilus desktop, with two black bars on top and bottom of the screen.
+>>>> If I launch a terminal, 'gnome-shell --replace' works fine.
+>>>>
+>>
+>> I reported this bug here:
+>>
+>> https://bugs.mageia.org/show_bug.cgi?id=2628
+>>
+>> I can reproduce it here on my x86-64 Mageia Linux Cauldron laptop.
+>>
+>> Regards,
+>>
+>> 	Shlomi Fish
+>>
+>>>> Any idea ?
+>>>> Can it be some personal setting ?
+>>>>
+>>>> TIA
+>>>
+>>> Digging a bit more, something is wrong detecting acceleration.
+>>> In GDM log:
+>>>
+>>> gnome-session[4752]: DEBUG(+): fill: *** Looking if /usr/share/gnome-session/sessions/gdm-shell.session is a valid session file
+>>> gnome-session[4752]: DEBUG(+): fill: *** Launching helper 'bash -c "gnome-shell --help | grep -q gdm-mode && /usr/lib64/gnome-session-check-accelerated"' to know if session is runnable
+>>> gnome-session-is-accelerated: No hardware 3D support.
+>>> gnome-session-check-accelerated: Helper exited with code 256
+>>> gnome-session[4752]: WARNING: Session 'gdm-shell' runnable check failed: Exited with code 1
+>>> gnome-session[4752]: DEBUG(+): fill: *** Session is not runnable
+>>> gnome-session[4752]: DEBUG(+): fill: *** Getting session 'gdm-fallback'
+>>>
+>>> This is for GDM's own session.
+>>> The same happens for user.
+>>>
+>>> Any ideas ? How can I check why this fails ?
+>>> Its a netbook with Intel graphics, so it uses Mesa.
+>>>
+>>> Will check on an nvidia system too.
+>>>
+> 
+> I did, and everything works fine. I even discovered that GDM looks different
+> when acceleration is available ;)).
+> 
+> So these are two separate problems:
+> 
+> - Acceleration detection on some systems, from my limited tests, it works on
+>   nVidia (32bit, will check 64 shortly), and fails on intel (mesa???) graphics.
+>   This can be a bug report for gnome-session (/usr/lib64/gnome-session-check-accelerated*)
+>   or for Mesa if it's it what breaks things.
+> 
+> - In full mode, gnome-shell from the user replaces gnome-shell from gdm.
+>   But in fallback mode, gnome-shell can't replace GDM's metacity.
+
+It's almost certainly a permissions thing.
+
+I'm not sure GDM registers itself with consolekit anymore. And
+in-so-doing, will not get permissions on the DRI device and thus will
+not be able to run the nice new shell.
+
+
+If you run systemd then all should be well.
+
+Col
+
+
+
+-- 
+
+Colin Guthrie
+mageia(at)colin.guthr.ie
+http://colin.guthr.ie/
+
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+