.
Thread 4 (LWP 6087):
#0  0x00007f04acb043cd in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007f04ad0452bc in g_main_context_pending (context=0x7f04ae724080) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3731
        retval = <optimized out>
#2  0x00007f04ae724080 in ?? ()
No symbol table info available.
#3  0xffffffff7fffffff in ?? ()
No symbol table info available.
#4  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 3 (LWP 6086):
#0  0x00007f04acb043cd in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007f04ad0452bc in g_main_context_pending (context=0x7f04ae6f6840) at /build/buildd/glib2.0-2.36.0/./glib/gmain.c:3731
        retval = <optimized out>
#2  0x00007f04ae6f6840 in ?? ()
No symbol table info available.
#3  0x000009967fffffff in ?? ()
No symbol table info available.
#4  0x00007f04ae6f0aa0 in ?? ()
No symbol table info available.
#5  0x00007f04ae7e09a0 in ?? ()
No symbol table info available.
#6  0x00007f04ae719520 in ?? ()
No symbol table info available.
#7  0x00007f04ae6f0aa0 in ?? ()
No symbol table info available.
#8  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 2 (LWP 6089):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
No locals.
#1  0x00007f04ad084b5f in g_system_thread_new (thread_func=0x1, stack_size=<optimized out>, error=0xffffffffffffffff) at /build/buildd/glib2.0-2.36.0/./glib/gthread-posix.c:1143
        thread = <optimized out>
        attr = {__size = "\260\350}\256\004\177\000\000\313\253\001\255\004\177\000\000P\350}\256\004\177", '\000' <repeats 18 times>, "`\220\024\256\004\177\000\000\020\255s9\377\177\000", __align = 139658084083888}
        ret = <optimized out>
        __PRETTY_FUNCTION__ = "g_system_thread_new"
#2  0x00007fff3973ad10 in ?? ()
No symbol table info available.
#3  0x0000000000001000 in ?? ()
No symbol table info available.
#4  0x00007f04ad0691d5 in g_thread_new_internal (name=0x7f04ae7de8b8 "\200\341}\256\004\177", proxy=<optimized out>, func=0x0, data=0x1000, stack_size=0, error=0x7f04ae149060) at /build/buildd/glib2.0-2.36.0/./glib/gthread.c:888
        thread = 0xfffffffffffffe00
#5  0x00007f04ae149060 in ?? ()
No symbol table info available.
#6  0x00007fff3973ad10 in ?? ()
No symbol table info available.
#7  0x0000000000001000 in ?? ()
No symbol table info available.
#8  0x17332c22eef5fde0 in ?? ()
No symbol table info available.
#9  0x17333c5c6c3bfde0 in ?? ()
No symbol table info available.
#10 0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (LWP 6088):
#0  gst_thumbnailer_play_start (cancellable=0x7f04a0006b30, play=0x0) at gst-thumbnailer.c:461
        bus = 0x0
        terminate = 0
        message = 0x0
        async_received = 0
#1  gst_thumbnailer_create (thumbnailer=0x7f04ae733de0, cancellable=0x7f04a0006b30, info=0x7f04ae7e3a80) at gst-thumbnailer.c:581
        play = 0x0
        pixbuf = 0x0
        duration = <optimized out>
        data = {colorspace = (unknown: 2927508688), data = 0x0, has_alpha = -1389189009, bits_per_sample = 32516, width = -1392115679, height = 0, rowstride = -1368374784}
        error = 0x0
        thumbnail = 0x7f0498003680
        width = <optimized out>
        height = <optimized out>
        flavor = <optimized out>
        scaled = 0x7f04a0006b30
#2  0x00007f04ae15b59c in tumbler_lifo_scheduler_thread (data=0x7f04ae7e3cd0, user_data=0x7f04a00050c0) at tumbler-lifo-scheduler.c:495
        request = 0x7f04ae7e3cd0
        scheduler = 0x7f04a00050c0
        uris = <optimized out>
        uri_needs_update = <optimized out>
        error = 0x0
        cached_uris = <optimized out>
        missing_uris = <optimized out>
        lp = 0x7f04ae780c80
        n = <optimized out>
        __PRETTY_FUNCTION__ = "tumbler_lifo_scheduler_thread"
#3  0x00007f04ad069a12 in g_thread_pool_new (func=<optimized out>, user_data=<optimized out>, max_threads=<optimized out>, exclusive=<optimized out>, error=<optimized out>) at /build/buildd/glib2.0-2.36.0/./glib/gthreadpool.c:513
        retval = <optimized out>
        g__init_lock = {p = 0x7f04ae7293e0, i = {2926744544, 32516}}
        __PRETTY_FUNCTION__ = "g_thread_pool_new"
#4  0x00007f04acde6f8e in start_thread (arg=0x7f04a5614700) at pthread_create.c:311
        __res = <optimized out>
        pd = 0x7f04a5614700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139657931212544, -1640887098479870496, 0, 139658077180000, 140734157270288, 4096, 1671731713232207328, 1671746254335114720}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = 0
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#5  0x00007f04acb10e1d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113
No locals.