.
Thread 2 (process 3884):
#0  0x00007f23eca16b8d in read () at ../sysdeps/unix/syscall-template.S:82
No locals.
#1  0x00007f23ea2d998b in child_watch_helper_thread (
    data=<value optimized out>)
    at /build/buildd/glib2.0-2.27.4/glib/gmain.c:4315
	b = "B\000\000\000\000\000\000\000\020�d�#\177\000\000\000\000\000"
	list = <value optimized out>
#2  0x00007f23ea2ff304 in g_thread_create_proxy (data=0x1f6f5f0)
    at /build/buildd/glib2.0-2.27.4/glib/gthread.c:1042
	thread = (GRealThread *) 0x1f6f5f0
	__PRETTY_FUNCTION__ = "g_thread_create_proxy"
#3  0x00007f23eca0f971 in start_thread (arg=<value optimized out>)
    at pthread_create.c:304
	__res = <value optimized out>
	pd = (struct pthread *) 0x7f23e764d710
	unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139792182728464, 
        2535564432475494395, 140733711522128, 139792182729168, 
        139792274972736, 3, -2488260083011479557, -2488244106382206981}, 
      mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {
      prev = 0x0, cleanup = 0x0, canceltype = 0}}}
	not_first_call = <value optimized out>
	robust = <value optimized out>
	freesize = <value optimized out>
	__PRETTY_FUNCTION__ = "start_thread"
#4  0x00007f23eb8e794d in ?? () from /lib/libc.so.6
	fstab_state = {fs_fp = 0x0, fs_buffer = 0x0, fs_mntres = {
    mnt_fsname = 0x0, mnt_dir = 0x0, mnt_type = 0x0, mnt_opts = 0x0, 
    mnt_freq = 0, mnt_passno = 0}, fs_ret = {fs_spec = 0x0, fs_file = 0x0, 
    fs_vfstype = 0x0, fs_mntops = 0x0, fs_type = 0x0, fs_freq = 0, 
    fs_passno = 0}}
	__elf_set___libc_subfreeres_element_fstab_free__ = (
    const void *) 0x7f23eb9336d0
#5  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (process 3854):
#0  0x00007f23e8405dc6 in pkgDepCache::ActionGroup::release (
    this=0xae00000044) at ../build/include/apt-pkg/cacheiterators.h:192
No locals.
#1  0x00007f23e86e0392 in PkgActionGroupExit (Self=<value optimized out>, 
    Args=<value optimized out>) at /usr/include/apt-pkg/cacheiterators.h:192
	ag = <value optimized out>
#2  0x0000000000423a87 in PyObject_CallFunctionObjArgs (callable=0x1ef7950)
    at ../Objects/abstract.c:381
	args = (PyObject *) 0x1ef67d0
	tmp = (PyObject *) 0x0
	vargs = {{gp_offset = 32, fp_offset = 48, 
    overflow_arg_area = 0x7fff1ee22620, reg_save_area = 0x7fff1ee22540}}
#3  0x0000003000000020 in ?? ()
No symbol table info available.
#4  0x00007fff1ee22620 in ?? ()
No symbol table info available.
#5  0x00007fff1ee22540 in ?? ()
No symbol table info available.
#6  0x000000000086e0c0 in ?? ()
No symbol table info available.
#7  0x000000000086e0c0 in ?? ()
No symbol table info available.
#8  0x00000000008793c0 in ?? ()
No symbol table info available.
#9  0x00000000008793c0 in ?? ()
No symbol table info available.
#10 0x00000000008793c0 in ?? ()
No symbol table info available.
#11 0x0000000000000000 in ?? ()
No symbol table info available.
Current language:  auto; currently asm
Current language:  auto; currently c++