.
Thread 1 (LWP 265):
#0  0xb77c4424 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb75f9b1f in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = <optimized out>
        resultvar = <optimized out>
        pid = -1216897024
        selftid = 265
#2  0xb75fd0b3 in __GI_abort () at abort.c:90
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x8000000, sa_sigaction = 0x8000000}, sa_mask = {__val = {0, 0, 67, 3078070272, 3076466421, 3076792005, 3077789265, 4294967295, 4294967295, 4294967295, 4294967295, 4294967295, 4294967295, 4294967295, 5, 4, 3076585713, 3078070272, 3077794565, 3075599759, 3221109400, 3078071360, 3078072704, 3077794565, 1, 3078070272, 3075600916, 3078070272, 3078072704, 0, 3, 4096}}, sa_flags = -1217694344, sa_restorer = 0xb777a000}
        sigs = {__val = {32, 0 <repeats 31 times>}}
#3  0xb75f2877 in __assert_fail_base (fmt=0xb7738674 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0xb751ed8f "backend != ((void *)0)", file=file@entry=0xb751ed78 "./plugin.c", line=line@entry=695, function=function@entry=0xb751f214 <__PRETTY_FUNCTION__.6829> "open_input_source") at assert.c:92
        str = 0x8c3ad58 "\310\272\314\bp\244w\267d: ./plugin.c:695: open_input_source: Assertion `backend != ((void *)0)' failed.\n"
        total = 4096
#4  0xb75f2927 in __GI___assert_fail (assertion=assertion@entry=0xb751ed8f "backend != ((void *)0)", file=file@entry=0xb751ed78 "./plugin.c", line=line@entry=695, function=function@entry=0xb751f214 <__PRETTY_FUNCTION__.6829> "open_input_source") at assert.c:101
No locals.
#5  0xb751ddfa in open_input_source (backend=<optimized out>, input_source=<optimized out>) at ./plugin.c:695
No locals.
#6  open_input_source (backend=0x0, input_source=0x8c38688) at ./plugin.c:690
        terminal_fd = <optimized out>
#7  0xb751dec3 in on_input_source_disconnected (input_source=0x8c38688) at ./plugin.c:686
        __func__ = "on_input_source_disconnected"
#8  0xb7798cf9 in ply_event_loop_handle_disconnect_for_source (source=0x8c37968, loop=0x8c2f0b0) at ply-event-loop.c:1089
        destination = 0x8cc9310
        next_node = 0x0
        node = <optimized out>
#9  ply_event_loop_disconnect_source (source=0x8c37968, loop=0x8c2f0b0) at ply-event-loop.c:1189
No locals.
#10 ply_event_loop_process_pending_events (loop=loop@entry=0x8c2f0b0) at ply-event-loop.c:1333
        source = 0x8c37968
        status = (unknown: 3075856008)
        is_disconnected = <optimized out>
        number_of_received_events = 1
        i = <optimized out>
        events = {{events = 25, data = {ptr = 0x8c37968, fd = 147028328, u32 = 147028328, u64 = 147028328}}, {events = 4294967295, data = {ptr = 0xffffffff, fd = -1, u32 = 4294967295, u64 = 18446744073709551615}} <repeats 63 times>}
        __PRETTY_FUNCTION__ = "ply_event_loop_process_pending_events"
#11 0xb77994c8 in ply_event_loop_run (loop=0x8c2f0b0) at ply-event-loop.c:1368
No locals.
#12 0x0804ba93 in main (argc=3, argv=0xbffe4034) at main.c:2561
        state = {loop = 0x8c2f0b0, boot_server = 0x8c31750, pixel_displays = 0x8c315f8, text_displays = 0x8c31608, keyboard = 0x8c39778, boot_splash = 0x8cce508, session = 0x8c31718, boot_buffer = 0x8c31708, progress = 0x8c34d28, keystroke_triggers = 0x8c305c0, entry_triggers = 0x8c305d0, entry_buffer = 0x8c305e0, messages = 0x8c31628, command_parser = 0x8c2f008, mode = PLY_MODE_BOOT, renderer = 0x8c35eb0, local_console_terminal = 0x8c35f08, deactivate_trigger = 0x0, quit_trigger = 0x0, kernel_command_line = "BOOT_IMAGE=/boot/vmlinuz-3.8.0-14-generic root=UUID=b01d3d2f-4852-4128-9fb9-6383cd070763 ro quiet splash\n", '\000' <repeats 406 times>, kernel_command_line_is_set = 1, no_boot_log = 0, showing_details = 1, system_initialized = 1, is_redirected = 0, is_attached = 0, should_be_attached = 1, should_retain_splash = 0, is_inactive = 1, should_force_details = 0, kernel_console_tty = 0x0, override_splash_path = 0x0, system_default_splash_path = 0x0, distribution_default_splash_path = 0x0, default_tty = 0x805647b "/dev/tty7", number_of_errors = 0, pending_messages = 0x8c31618}
        exit_code = <optimized out>
        should_help = false
        no_daemon = false
        debug = false
        attach_to_session = true
        daemon_handle = 0x8c2f558
        mode_string = 0x8c2f558 "PN\303\bPN\303\b\001"
        kernel_command_line = 0x0
        tty = 0x0
        __func__ = "main"