Comment 23 for bug 232364

Forwarding a Ubuntu bug:
https://bugs.edge.launchpad.net/ubuntu/+source/libxcb/+bug/232364

A number of Xubuntu users have been experiencing failures on startup when launching dbus-launch. Backtraces indicate the problem always occurs during a select() call in _xcb_in_read_block. The freezes are intermittently reproducible (i.e., restart several times and eventually it'll come up).

(gdb) bt
#0 0xb8002424 in __kernel_vsyscall ()
#1 0xb7e8484d in select () from /lib/tls/i686/cmov/libc.so.6
#2 0xb7da309a in _xcb_in_read_block (c=0x80579a8, buf=0x8057040, len=8)
    at xcb_in.c:248
#3 0xb7da2343 in xcb_connect_to_fd (fd=13, auth_info=0xbff1cdf0)
    at xcb_conn.c:133
#4 0xb7da4a51 in xcb_connect (displayname=0x0, screenp=0x0) at xcb_util.c:279
#5 0xb7f43717 in _XConnectXCB () from /usr/lib/libX11.so.6
#6 0xb7f2c029 in XOpenDisplay () from /usr/lib/libX11.so.6
#7 0x0804b3de in x11_init () at dbus-launch-x11.c:218
#8 0x0804abb2 in main (argc=5, argv=0xbff1d5a4) at dbus-launch.c:432
(gdb) quit

strace also shows that the hang is occurring on a select call:

  select(14, [13], NULL, NULL, NULL