#0  0xb76ea424 in __kernel_vsyscall ()
#1  0xb7286b1f in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
  [Error: ../nptl/sysdeps/unix/sysv/linux/raise.c was not found in source tree]
#2  0xb728a0b3 in __GI_abort () at abort.c:90
  [Error: abort.c was not found in source tree]
#3  0xb72c3ab5 in __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0xb73c6530 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:199
  [Error: ../sysdeps/unix/sysv/linux/libc_fatal.c was not found in source tree]
#4  0xb72ce7e2 in malloc_printerr (action=<optimized out>, str=<optimized out>, ptr=0x9b65738) at malloc.c:4902
  [Error: malloc.c was not found in source tree]
#5  0xb72cf530 in _int_free (av=0xb7407440 <main_arena>, p=0x9b65730, have_lock=0) at malloc.c:3758
  [Error: malloc.c was not found in source tree]
#6  0xb747551b in standard_free (mem=0x9b65738) at /build/buildd/glib2.0-2.35.8/./glib/gmem.c:98
  [Error: /build/buildd/glib2.0-2.35.8/./glib/gmem.c was not found in source tree]
#7  0xb7475690 in g_free (mem=mem@entry=0x9b65738) at /build/buildd/glib2.0-2.35.8/./glib/gmem.c:252
  [Error: /build/buildd/glib2.0-2.35.8/./glib/gmem.c was not found in source tree]
#8  0xb76d8e8d in initialize_backend (cbdav=cbdav@entry=0x9b3d850, perror=perror@entry=0xb123b1dc) at e-cal-backend-caldav.c:2685
  2680: 	if (cbdav->priv->uri && *cbdav->priv->uri) {
  2681: 		gchar *tmp = cbdav->priv->uri;
  2682: 
  2683: 		cbdav->priv->uri = g_strconcat (cbdav->priv->uri, "/", NULL);
  2684: 
  2685: 		g_free (tmp);
  2686: 	}
  2687: 
  2688: 	g_signal_handlers_unblock_by_func (cbdav->priv->proxy, proxy_settings_changed, cbdav);
  2689: 
  2690: 	if (cbdav->priv->store == NULL) {
#9  0xb76dfa86 in caldav_do_open (backend=0x9b3d850, cal=0x9b42198, cancellable=0x9b42d80, only_if_exists=1, perror=0xb123b1dc) at e-cal-backend-caldav.c:2787
  2782: 	g_mutex_lock (cbdav->priv->busy_lock);
  2783: 
  2784: 	/* let it decide the 'getctag' extension availability again */
  2785: 	cbdav->priv->ctag_supported = TRUE;
  2786: 
  2787: 	if (!cbdav->priv->loaded && !initialize_backend (cbdav, perror)) {
  2788: 		g_mutex_unlock (cbdav->priv->busy_lock);
  2789: 		return;
  2790: 	}
  2791: 
  2792: 	online = e_backend_get_online (E_BACKEND (backend));
#10 0xb76a8207 in e_cal_backend_sync_open (backend=0x9b3d850, cal=cal@entry=0x9b42198, cancellable=cancellable@entry=0x9b42d80, only_if_exists=only_if_exists@entry=1, error=error@entry=0xb123b1dc) at e-cal-backend-sync.c:89
  84:                          gboolean only_if_exists,
  85:                          GError **error)
  86: {
  87: 	e_return_data_cal_error_if_fail (backend && E_IS_CAL_BACKEND_SYNC (backend), InvalidArg);
  88: 
  89: 	LOCK_WRAPPER (open_sync, (backend, cal, cancellable, only_if_exists, error));
  90: }
  91: 
  92: /**
  93:  * e_cal_backend_sync_remove:
  94:  * @backend: An ECalBackendSync object.
#11 0xb76a83d5 in cal_backend_open (backend=0x9b3d850, cal=0x9b42198, opid=1, cancellable=0x9b42d80, only_if_exists=1) at e-cal-backend-sync.c:578
  573:                   GCancellable *cancellable,
  574:                   gboolean only_if_exists)
  575: {
  576: 	GError *error = NULL;
  577: 
  578: 	e_cal_backend_sync_open (E_CAL_BACKEND_SYNC (backend), cal, cancellable, only_if_exists, &error);
  579: 
  580: 	e_data_cal_respond_open (cal, opid, error);
  581: }
  582: 
  583: static void
#12 0xb76a308b in e_cal_backend_open (backend=backend@entry=0x9b3d850, cal=0x9b42198, opid=1, cancellable=0x9b42d80, only_if_exists=1) at e-cal-backend.c:905
  900: 		e_data_cal_respond_open (cal, opid, EDC_OPENING_ERROR);
  901: 	} else {
  902: 		backend->priv->opening = TRUE;
  903: 		g_mutex_unlock (backend->priv->clients_mutex);
  904: 
  905: 		(* E_CAL_BACKEND_GET_CLASS (backend)->open) (backend, cal, opid, cancellable, only_if_exists);
  906: 	}
  907: }
  908: 
  909: /**
  910:  * e_cal_backend_remove:
#13 0xb76b1c7c in operation_thread (data=0x9b42d60, user_data=0x0) at e-data-cal.c:183
  178: 
  179: 	backend = e_data_cal_get_backend (op->cal);
  180: 
  181: 	switch (op->op) {
  182: 	case OP_OPEN:
  183: 		e_cal_backend_open (backend, op->cal, op->id, op->cancellable, op->d.only_if_exists);
  184: 		break;
  185: 	case OP_REMOVE:
  186: 		e_cal_backend_remove (backend, op->cal, op->id, op->cancellable);
  187: 		break;
  188: 	case OP_REFRESH:
#14 0xb7495b58 in g_thread_pool_thread_proxy (data=0x9b25c60) at /build/buildd/glib2.0-2.35.8/./glib/gthreadpool.c:309
  [Error: /build/buildd/glib2.0-2.35.8/./glib/gthreadpool.c was not found in source tree]
#15 0xb7495143 in g_thread_proxy (data=0x9c37090) at /build/buildd/glib2.0-2.35.8/./glib/gthread.c:798
  [Error: /build/buildd/glib2.0-2.35.8/./glib/gthread.c was not found in source tree]
#16 0xb7412d78 in start_thread (arg=0xb123bb40) at pthread_create.c:311
  [Error: pthread_create.c was not found in source tree]
#17 0xb73493de in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131
  [Error: ../sysdeps/unix/sysv/linux/i386/clone.S was not found in source tree]