.
Thread 4 (LWP 2369):
#0  0x00007f700024583d in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007f700077c33c in ?? ()
No symbol table info available.
#2  0x0000000000000020 in ?? ()
No symbol table info available.
#3  0x00000001015dc080 in ?? ()
No symbol table info available.
#4  0xffffffff7fffffff in ?? ()
No symbol table info available.
#5  0x3dddc67ba6759c00 in ?? ()
No symbol table info available.
#6  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 3 (LWP 2370):
#0  0x00007f70005244fd in nanosleep () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007f70007a4208 in ?? ()
No symbol table info available.
#2  0x000000000000000f in ?? ()
No symbol table info available.
#3  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 2 (LWP 2368):
#0  0x00007f700024583d in poll () at ../sysdeps/unix/syscall-template.S:81
No locals.
#1  0x00007f700077c33c in ?? ()
No symbol table info available.
#2  0x00007fff9dd8a83f in ?? ()
No symbol table info available.
#3  0x00000001015dcf20 in ?? ()
No symbol table info available.
#4  0xffffffff7fffffff in ?? ()
No symbol table info available.
#5  0x3dddc67ba6759c00 in ?? ()
No symbol table info available.
#6  0x00007fff9dd8a83f in ?? ()
No symbol table info available.
#7  0x00000000015ee330 in ?? ()
No symbol table info available.
#8  0x0000000000000001 in ?? ()
No symbol table info available.
#9  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (LWP 2367):
#0  0x00007f6fffbb8b2c in ?? ()
No symbol table info available.
#1  0x00000000000000ea in ?? ()
No symbol table info available.
#2  0x00007f70018a500e in ev_document_misc_surface_rotate_and_scale () from /tmp/apport_sandbox_rJORCp/usr/lib/x86_64-linux-gnu/libatrildocument.so.3
No symbol table info available.
#3  0x00007f6ff9c65b05 in epub_document_thumbnails_get_thumbnail () from /tmp/apport_sandbox_rJORCp/usr/lib/x86_64-linux-gnu/atril/3/backends/libepubdocument.so
No symbol table info available.
#4  0x0000000000401b2a in atril_thumbnail_pngenc_get ()
No symbol table info available.
#5  0x000000000040177c in main ()
No symbol table info available.