(gdb) bt #0 ___pthread_mutex_lock (mutex=0x7f5cac038) at pthread_mutex_lock.c:80 #1 0x00007f5cb569a7e0 in __gthread_mutex_lock (__mutex=0x7f5cac038) at /usr/include/x86_64-linux-gnu/c++/11/bits/gthr-default.h:749 #2 std::mutex::lock (this=0x7f5cac038) at /usr/include/c++/11/bits/std_mutex.h:100 #3 std::scoped_lock<std::mutex>::scoped_lock (__m=..., this=<synthetic pointer>) at /usr/include/c++/11/mutex:655 #4 HAL_StopNotifier (notifierHandle=<optimized out>, status=<optimized out>) at /work/hal/src/main/native/sim/Notifier.cpp:200 #5 0x00007f5cb122f541 in (anonymous namespace)::HeartbeatDaemon::Main() () from /home/virtuald/src/frc/robotpy-rev/rev/_rev.cpython-38-x86_64-linux-gnu.so #6 0x00007f5cb5939c4b in operator() (__closure=0x5587df615988) at /work/wpiutil/src/main/native/cpp/SafeThread.cpp:79 #7 std::__invoke_impl<void, wpi::detail::SafeThreadOwnerBase::Start(std::shared_ptr<wpi::SafeThreadBase>)::<lambda()> > (__f=...) at /usr/include/c++/11/bits/invoke.h:61 #8 std::__invoke<wpi::detail::SafeThreadOwnerBase::Start(std::shared_ptr<wpi::SafeThreadBase>)::<lambda()> > (__fn=...) at /usr/include/c++/11/bits/invoke.h:96 #9 std::thread::_Invoker<std::tuple<wpi::detail::SafeThreadOwnerBase::Start(std::shared_ptr<wpi::SafeThreadBase>)::<lambda()> > >::_M_invoke<0> (this=0x5587df615988) at /usr/include/c++/11/bits/std_thread.h:259 #10 std::thread::_Invoker<std::tuple<wpi::detail::SafeThreadOwnerBase::Start(std::shared_ptr<wpi::SafeThreadBase>)::<lambda()> > >::operator() (this=0x5587df615988) at /usr/include/c++/11/bits/std_thread.h:266 #11 std::thread::_State_impl<std::thread::_Invoker<std::tuple<wpi::detail::SafeThreadOwnerBase::Start(std::shared_ptr<wpi::SafeThreadBase>)::<lambda()> > > >::_M_run(void) (this=0x5587df615980) at /usr/include/c++/11/bits/std_thread.h:211 #12 0x00007f5cb54e31e3 in std::execute_native_thread_routine (__p=0x5587df615980) at ../../../../../libstdc++-v3/src/c++11/thread.cc:104 #13 0x00007f5cc36ac897 in start_thread (arg=<optimized out>) at pthread_create.c:444 #14 0x00007f5cc373380c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78