(gdb) bt
#0  0x00216424 in __kernel_vsyscall ()
#1  0x00eff965 in sigtimedwait () from /lib/libc.so.6
#2  0x00b9c438 in boost::throw_exception<boost::bad_function_call> (e=...) at /usr/include/boost/throw_exception.hpp:57
#3  0x00b9c57d in ~bad_function_call (e=...) at /usr/include/boost/function/function_base.hpp:732
#4  ~error_info_injector (e=...) at /usr/include/boost/exception/exception.hpp:275
#5  boost::throw_exception<boost::bad_function_call> (e=...) at /usr/include/boost/throw_exception.hpp:64
#6  0x00b9a10b in _S_right (this=0xbfb68228, task_id=@0xb49ff2a0)
    at /usr/lib/gcc/i686-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/stl_tree.h:517
#7  _M_insert_unique (this=0xbfb68228, task_id=@0xb49ff2a0)
    at /usr/lib/gcc/i686-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/stl_tree.h:1171
#8  insert (this=0xbfb68228, task_id=@0xb49ff2a0) at /usr/lib/gcc/i686-redhat-linux/4.4.7/../../../../include/c++/4.4.7/bits/stl_set.h:411
...