(gdb) bt full
#0  0x0000555556d6edc2 in ccl::ImageManager::device_free_image(ccl::Device*, ccl::DeviceScene*, ccl::ImageDataType, int) ()
No symbol table info available.
#1  0x0000555556d6ef77 in ccl::ImageManager::device_free(ccl::Device*, ccl::DeviceScene*) ()
No symbol table info available.
#2  0x0000555556dd1475 in ccl::Scene::free_memory(bool) ()
No symbol table info available.
#3  0x0000555556dd4b06 in ccl::Session::device_free() ()
No symbol table info available.
#4  0x0000555556d14008 in ccl::BlenderSession::render() ()
No symbol table info available.
#5  0x0000555556d0d5c8 in ccl::render_func(_object*, _object*) ()
No symbol table info available.
#6  0x00007ffff71f7417 in PyEval_EvalFrameEx () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#7  0x00007ffff71f763b in PyEval_EvalFrameEx () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#8  0x00007ffff72b7a64 in ?? () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#9  0x00007ffff72b7b43 in PyEval_EvalCodeEx () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#10 0x00007ffff7139d18 in ?? () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#11 0x00007ffff7227447 in PyObject_Call () from /usr/lib/x86_64-linux-gnu/libpython3.5m.so.1.0
No symbol table info available.
#12 0x000055555639acbe in bpy_class_call ()
No symbol table info available.
#13 0x000055555684f471 in engine_render ()
No symbol table info available.
#14 0x000055555631b173 in RE_engine_render ()
No symbol table info available.
#15 0x000055555632d899 in do_render_3d ()
No symbol table info available.
#16 0x000055555632f45e in RE_PreviewRender ()
No symbol table info available.
#17 0x0000555556279c5f in shader_preview_render ()
No symbol table info available.
#18 0x0000555556279e01 in shader_preview_startjob ()
No symbol table info available.
#19 0x000055555627a28e in common_preview_startjob ()
No symbol table info available.
#20 0x000055555627a562 in icon_preview_startjob_all_sizes ()
No symbol table info available.
#21 0x0000555555fbf43a in do_job_thread ()
No symbol table info available.
#22 0x00007ffff3e59494 in start_thread (arg=0x7fff9fffc700) at pthread_create.c:333
        __res = <optimized out>
        pd = 0x7fff9fffc700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140735877728000, 4685496192209213015, 0, 140737488342559, 140735877728000, 140736049882784, -4685707300758661545, -4685469581888104873}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0,
              cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#23 0x00007fffef45893f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97
No locals.