pidgin crashes with _XGetXCBBuffer: Assertion `((int) ((xcb_req) - (dpy->request)) >= 0)' failed

[Stuart Langridge]

Binary package hint: pidgin

Pidgin sometimes terminates with the following error:

pidgin: ../../src/xcb_lock.c:77: _XGetXCBBuffer: Assertion `((int) ((xcb_req) - (dpy->request)) >= 0)' failed.
Aborted

It sometimes crashes when I'm using it, and sometimes when I'm afk.

Pidgin 2.4.1 in Hardy

[alan ezust (alan-ezust)]

I can confirm this on debian lenny also. I encountered this just after an upgrade today.

[Eemil Lagerspetz (eemil-lagerspetz)]

Hi, this occurs with my pidgin 2.4.3 and Hardy 64-bit too.

[Adam Katz (khopesh)]

Debian Lenny, pidgin 2.4.3-2, skype (via apt) 2.0.0.72-1, libxcb-render-util0 0.2.1+git1-1, libxcb1 1.1-1.1, dev versions of xcb packages are installed (total of 11 related libxcb* packages installed at above versions). As of September, this is still a bug.

However, this is NOT a bug with pidigin, as noted at http://developer.pidgin.im/ticket/6367

The relevant bug is registered at http://code.google.com/p/skype4pidgin/issues/detail?id=18

A search for the error message revealed this tip: http://www.linuxquestions.org/linux/blog/Vermind/2008-08-01/Skype_Pidgin_Plugin ... but setting LIBXCB_ALLOW_SLOPPY_LOCK=1 does not solve this for me (or at least, it doesn't fully solve the issue; either it reduced my crash frequency or I've been less popular since trying it), and I'm less interested in a custom xcb-lacking build of libX11 (which would certainly solve the issue).

[adesmarais (yagogak)]

Hi,

Same problem with synergy on ubuntu 8.10

synergyc: ../../src/xcb_lock.c:77: _XGetXCBBuffer: Assertion `((int) ((xcb_req) - (dpy->request)) >= 0)' failed.

[Eemil Lagerspetz (eemil-lagerspetz)]

The bug persists with pidgin 2.5.2, newest pidgin skype plugin (oct 28) and Ubuntu Intrepid 8.10 32-bit and 64-bit.

[Fabián Rodríguez (magicfab)]

Workaround (tested in Hardy):

- Download libskype.so from http://code.google.com/p/skype4pidgin/issues/detail?id=18
- sudo cp Desktop/libskype.so /usr/lib/purple-2/.

The replacement file comes from upstream, a new package should be built soon I imagine once enough people has tested this.

[Adam Katz (khopesh)]

As of 2008-11-19, a new version of skype4pidgin was released with that fix. You should be able to upgrade to the latest version and this problem should go away. http://eion.robbmob.com/

I've been using it for a few hours without any issues, but it only crashed about once a week for me beforehand.

The .deb looks pretty usable now. Maybe it will find its way into Debian Sid?

[Adam Katz (khopesh)]

I hope I'm not stepping beyond my rights in changing the status and taking the bug...

I'm respecting the original "Confirmed" status while marking it "Fix Released" rather than "Invalid" the way Pidgin and others have marked similar bugs. (This bug should have been flagged "Invalid" because it was a bug with the 'skype4pidgin' package/plugin rather than for Pidgin itself, and there is no such package within the Debian or Ubuntu repositories. A better status would be a bugzilla-styled "Worksforme")

Of course, that makes it odd for this bug to have a resolution of "Fix Released" since the "release" part of that has nothing to do with Ubuntu, but presumably anybody who had this bug found the plugin before and can find it again (hint: look at the comments above).

I use Skype via pidgin every day, and I haven't had skype4pidgin cause this XCB crash since before my last comment. There have been no other posts noting that this is still a problem, and the skype4pidgin site has confirmed the fix (including on Ubuntu itself) and closed the corresponding bug. Time to close this one, too.

[Eemil Lagerspetz (eemil-lagerspetz)]

Yes, pidgin4skype fixed this bug in the version on Nov 2008. Since then I have not encountered this either.