Re: [gnome-flashback] Gnome FB Meta on F22 fails to start locally

[Michael DePaulo <mikedep333 gmail com>]

On Mon, Aug 10, 2015 at 7:08 AM, Alberts Muktupāvels
<alberts muktupavels gmail com> wrote:
> On Mon, Aug 10, 2015 at 1:57 PM, Yaakov Selkowitz <yselkowi redhat com>
> wrote:
> > On Mon, 2015-08-10 at 12:09 +0300, Alberts Muktupāvels wrote:
> > > On Mon, Aug 10, 2015 at 9:32 AM, Yaakov Selkowitz wrote:
> > > > I had the same issue on a Lenovo Thinkpad T540p.  gnome-flashback
> > > > crashes in flashback_monitor_manager_read_current_config(), and I
> > > > was
> > > > able to work around it by setting the org.gnome.gnome-flashback
> > > > display
> > > > -config key to false (at the price of losing the Display control
> > > > panel
> > > > functionality).
> > > >
> > > > As for a proper fix, please let me know if you need any further
> > > > information to help diagnose the issue.
> > > gdb output? And if you can please test with git master - there was
> > > changes in display code.
> >
> > Still crashes with git master.
>
>
>
> Thanks! I will look at this when I will have more free time... Can you test
> with mutter?

Mutter 3.16.3-2 in 64-bit Fedora 22 does not segfault. I am able to
run a regular GNOME session, and a GNOME Classic session,
successfully.
http://pkgs.fedoraproject.org/cgit/mutter.git/log/?h=f22

At 1st glance, this Fedora 22 patch for mutter *might* be related:
http://pkgs.fedoraproject.org/cgit/mutter.git/tree/0001-Force-cursor-update-after-applying-configuration.patch?h=f22&id=e6fa8a042f8e98b4827c308ebe242bbbdb7f84d6

> > Backtrace from systemd-coredump:
> >
> > #0  0x0000000000421f44 read_current_config (gnome-flashback)
> > #1  0x0000000000423757 flashback_monitor_manager_read_current_config
> > (gnome-flashback)
> > #2  0x00000000004223d5 flashback_monitor_manager_constructed (gnome
> > -flashback)
> > #3  0x00000037dc015627 g_object_new_internal (libgobject-2.0.so.0)
> > #4  0x00000037dc016f45 g_object_new_valist (libgobject-2.0.so.0)
> > #5  0x00000037dc0172b1 g_object_new (libgobject-2.0.so.0)
> > #6  0x00000000004228c4 flashback_monitor_manager_new (gnome-flashback)
> > #7  0x000000000041a92b flashback_display_config_init (gnome-flashback)
> > #8  0x00000037dc03256b g_type_create_instance (libgobject-2.0.so.0)
> > #9  0x00000037dc0150ab g_object_new_internal (libgobject-2.0.so.0)
> > #10 0x00000037dc016991 g_object_newv (libgobject-2.0.so.0)
> > #11 0x00000037dc0172c4 g_object_new (libgobject-2.0.so.0)
> > #12 0x000000000041a991 flashback_display_config_new (gnome-flashback)
> > #13 0x000000000041231f settings_changed (gnome-flashback)
> > #14 0x0000000000412c9c flashback_application_init (gnome-flashback)
> > #15 0x00000037dc03256b g_type_create_instance (libgobject-2.0.so.0)
> > #16 0x00000037dc0150ab g_object_new_internal (libgobject-2.0.so.0)
> > #17 0x00000037dc016991 g_object_newv (libgobject-2.0.so.0)
> > #18 0x00000037dc0172c4 g_object_new (libgobject-2.0.so.0)
> > #19 0x0000000000412d35 flashback_application_new (gnome-flashback)
> > #20 0x0000000000412f1d main (gnome-flashback)
> > #21 0x00000037d9020700 __libc_start_main (libc.so.6)
> > #22 0x0000000000411df9 _start (gnome-flashback)
> >
> > $ addr2line -Cfpe /usr/bin/gnome-flashback 0x421f44
> > read_current_config at gnome-flashback/libdisplay-config/flashback
> > -monitor-manager.c:1296
> >
> > which is:
> >
> >           meta_output->preferred_mode = meta_output->modes[0];
> >
> > Adding some g_warning calls shows that on the first run of
> > read_current_config(), meta_output->n_modes and manager->n_modes are
> > both 1, but on subsequent calls they are 0 and 1 respectively, which
> > leads to this NULL reference.
> >
> > This is a Lenovo ThinkPad T540p running F22.
[...]

Mine is an Acer C720P Chromebook (Haswell mobile graphics) running the
default SeaBIOS. I am using 64-bit Fedora 22 with the latest stable
updates, which means kernel 4.1.

-Mike