#0  0x00007f695f2367fc in QMutex::lock() () from /usr/lib/libQtCore.so.4
No symbol table info available.
#1  0x00007f69505d48b2 in ?? ()
   from /usr/lib/soprano/libsoprano_virtuosobackend.so
No symbol table info available.
#2  0x00007f695b4e7226 in ?? () from /usr/lib/libsoprano.so.4
No symbol table info available.
#3  0x00007f695f25793d in QHashData::free_helper(void (*)(QHashData::Node*))
    () from /usr/lib/libQtCore.so.4
No symbol table info available.
#4  0x00007f6953b02489 in ?? () from /usr/lib/libsopranoserver.so.1
No symbol table info available.
#5  0x00007f695f23b6b5 in ?? () from /usr/lib/libQtCore.so.4
No symbol table info available.
#6  0x00007f695efabb14 in start_thread (arg=<value optimized out>)
    at pthread_create.c:300
        __res = <value optimized out>
        pd = 0x7f694ca2d710
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140090234033936, 
                -5460775335622733931, 140735539620944, 140090234033936, 0, 3, 
                5396988586348122005, 5396948661844971413}, 
              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"
#7  0x00007f695d3c005d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
No locals.
#8  0x0000000000000000 in ?? ()
No symbol table info available.