Debug assertion failure in OSX CI.

Author: insertinterestingnamehere

.github/workflows/CI.yml

@@ -233,6 +233,8 @@ jobs:
         ./configure $QTHREADS_ENABLE_ASSERTS --enable-picky --with-scheduler=${{ matrix.scheduler }} --with-topology=${{ matrix.topology }}
         make -j3
         make tests -j3
+        echo "settings set target.process.stop-on-exec false" > ~/.lldbinit
+        QT_NUM_SHEPHERDS=2 QT_NUM_WORKERS_PER_SHEPHERD=1 lldb bash --batch --one-line 'process launch' --one-line-on-crash 'bt' --one-line-on-crash 'quit' -- test/basics/hello_world
     - name: make check
       run: |
         # commented example for how to get a backtrace from CI usign lldb on OSX:

include/qt_atomics.h

@@ -161,6 +161,7 @@ static inline int QTHREAD_TRYLOCK_TRY(qt_spin_trylock_t *x) {
     }                                                                          \
     {                                                                          \
       pthread_condattr_t tmp_attr;                                             \
+      pthread_condattr_init(&tmp_attr);                                        \
       qassert(pthread_condattr_setpshared(&tmp_attr, PTHREAD_PROCESS_PRIVATE), \
               0);                                                              \
       QTHREAD_SET_CONDATTR_CLOCK(tmp_attr);                                    \