.
Thread 2 (Thread 0x7fb8585ef700 (LWP 1253)):
#0  0x00007fb85e868ca4 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1  0x00007fb85b845d4b in ?? () from /usr/lib/x86_64-linux-gnu/dri/r600_dri.so
No symbol table info available.
#2  0x00007fb85e864f8e in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#3  0x00007fb85d581e1d in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
.
Thread 1 (Thread 0x7fb85f72d980 (LWP 1251)):
#0  0x00007fb85d4bf037 in raise () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
Cannot access memory at address 0x7fffc39d81f8