Here's another that just happened to me in case it helps. Used pstack to get all threads.
pstack 15223
Thread 13 (Thread 0x7fed4937a700 (LWP 15245)):
#0 0x00007fed5e864a35 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a3d in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x00000000005528bf in WildcardCacheThread::run() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 12 (Thread 0x7fed408c3700 (LWP 15247)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36977 in slickedit::SEListTagsThread::runAsReader() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 11 (Thread 0x7fed407c2700 (LWP 15248)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36977 in slickedit::SEListTagsThread::runAsReader() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 10 (Thread 0x7fed406c1700 (LWP 15249)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36f0d in slickedit::SEListTagsThread::runAsTagger() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 9 (Thread 0x7fed405c0700 (LWP 15250)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36f0d in slickedit::SEListTagsThread::runAsTagger() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 8 (Thread 0x7fed404bf700 (LWP 15251)):
#0 0x00007fed5e867e9d in nanosleep () from /lib64/libpthread.so.0
#1 0x0000000002331f78 in cmThread::sleep(int) ()
#2 0x00000000006d68d6 in hfile_t::bufLockBoth(int) ()
#3 0x00000000006d6f3b in vsBufGetModifyFlags ()
#4 0x0000000001c0ace5 in slickedit::SEListTagsTarget::updateBufferModifyFlags() ()
#5 0x0000000001c0e372 in slickedit::SEListTagsTarget::insertAsynchronousTagsInContext() ()
#6 0x0000000001c37598 in slickedit::SEListTagsThread::runAsTagger() ()
#7 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#8 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#9 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 7 (Thread 0x7fed403be700 (LWP 15252)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36f0d in slickedit::SEListTagsThread::runAsTagger() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 6 (Thread 0x7fed402bd700 (LWP 15253)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c36f0d in slickedit::SEListTagsThread::runAsTagger() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 5 (Thread 0x7fed401bc700 (LWP 15254)):
#0 0x00007fed5e864de2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a0c in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x0000000001c377a4 in slickedit::SEListTagsThread::runAsWriter() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 4 (Thread 0x7fed3acfd700 (LWP 15256)):
#0 0x00007fed5e867e9d in nanosleep () from /lib64/libpthread.so.0
#1 0x0000000002331f78 in cmThread::sleep(int) ()
#2 0x00000000026c0b15 in SVNStatusThread::run() ()
#3 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#4 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#5 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 3 (Thread 0x7fed3abfc700 (LWP 15267)):
#0 0x00007fed5e864a35 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1 0x0000000002332a3d in cmWaitable::cond_wait(int) ()
#2 0x0000000002332d53 in cmWaitHandle::waitOne(int) ()
#3 0x00000000026b88ae in fileDateThread::run() ()
#4 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#5 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#6 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 2 (Thread 0x7fed3aafb700 (LWP 5707)):
#0 0x00007fed5e867e9d in nanosleep () from /lib64/libpthread.so.0
#1 0x0000000002331f78 in cmThread::sleep(int) ()
#2 0x00000000026caa4a in GitStatusThread::run() ()
#3 0x0000000002330b77 in cmThread::ThreadStartRoutine(void*) ()
#4 0x00007fed5e860ea5 in start_thread () from /lib64/libpthread.so.0
#5 0x00007fed54ec296d in clone () from /lib64/libc.so.6
Thread 1 (Thread 0x7fed5ebe1940 (LWP 15223)):
#0 0x00007fed54eb7c3d in poll () from /lib64/libc.so.6
#1 0x00007fed548f837c in g_main_context_iterate.isra.19 () from /lib64/libglib-2.0.so.0
#2 0x00007fed548f84ac in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#3 0x00007fed5ca00784 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#4 0x00007fed5cde5d66 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#5 0x00007fed5c9d324f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#6 0x00007fed5c9d3555 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#7 0x00007fed5d23e81c in QDialog::exec() () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#8 0x0000000001eb9df8 in vmessage_box(QWidget*, char const*, char const*, int, int, VFONT*) ()
#9 0x00000000006a0fcb in vsMessageBox ()
#10 0x00000000006a11bc in retry() ()
#11 0x00000000009b15e2 in VSHBLOCKTAB::btRetry() ()
#12 0x00000000009b1620 in VSHBLOCKTAB::btRetryLSeek(long long) ()
#13 0x00000000009b1f79 in VSHBLOCKTAB::btReadSpillBlock(cmEdMemBlock*, hfile_t*, cmEdBlock*, hfile_t*) ()
#14 0x00000000009c86b5 in hreadspillblock(hfile_t*, bool, cmEdBlock*) ()
#15 0x0000000000865c2a in hgetundoblock(cmEdMemBlockRef&, undo_dm_t*, hfile_t*) ()
#16 0x0000000000865f67 in hTruncateUndoStack(hfile_t*) ()
#17 0x0000000000866248 in hallocundodata(cmEdMemBlockRef&, int, hfile_t*) ()
#18 0x00000000008667c9 in maybe_record_mark(hfile_t*, bool, bool) [clone .constprop.42] ()
#19 0x0000000000868fce in hstart_recording(fileview_t*, bool, bool) ()
#20 0x00000000007fffdb in vsaexecutelstr(unsigned char const*, int, cmStringT<char, 1, 30> const&) ()
#21 0x00000000008004e0 in vsaExecute(char const*, char const*) ()
#22 0x0000000000800ecb in vsExecute ()
#23 0x000000000063dd80 in concur_readwrite(VSCONCURSHELL_INFO*) ()
#24 0x00007fed5c9e6d90 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#25 0x00007fed5c9ebc03 in QObject::event(QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#26 0x00007fed5cd49dac in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#27 0x00007fed5cd50523 in QApplication::notify(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#28 0x00007fed5c9d4a7d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#29 0x00007fed5ca02958 in QTimerInfoList::activateTimers() () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#30 0x00007fed5c9ffe11 in timerSourceDispatch(_GSource*, int (*)(void*), void*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#31 0x00007fed548f8099 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#32 0x00007fed548f83f8 in g_main_context_iterate.isra.19 () from /lib64/libglib-2.0.so.0
#33 0x00007fed548f84ac in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#34 0x00007fed5ca00784 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#35 0x00007fed5cde5d66 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#36 0x00007fed5c9d324f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#37 0x00007fed5c9d3555 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#38 0x00007fed5d23e81c in QDialog::exec() () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#39 0x0000000001eb9df8 in vmessage_box(QWidget*, char const*, char const*, int, int, VFONT*) ()
#40 0x00000000006a0fcb in vsMessageBox ()
#41 0x00000000006a11bc in retry() ()
#42 0x00000000009b15e2 in VSHBLOCKTAB::btRetry() ()
#43 0x00000000009b1f69 in VSHBLOCKTAB::btReadSpillBlock(cmEdMemBlock*, hfile_t*, cmEdBlock*, hfile_t*) ()
#44 0x00000000009c86b5 in hreadspillblock(hfile_t*, bool, cmEdBlock*) ()
#45 0x0000000000865c2a in hgetundoblock(cmEdMemBlockRef&, undo_dm_t*, hfile_t*) ()
#46 0x000000000086619c in hallocundodata(cmEdMemBlockRef&, int, hfile_t*) ()
#47 0x00000000008667c9 in maybe_record_mark(hfile_t*, bool, bool) [clone .constprop.42] ()
#48 0x0000000000868fce in hstart_recording(fileview_t*, bool, bool) ()
#49 0x000000000083e22b in p_undo_status_op() ()
#50 0x0000000000808453 in pmethod_op() ()
#51 0x0000000000616f52 in run_proc(int) ()
#52 0x0000000000617299 in run_proc_immediate2(m_s*, int, int, VSARGTYPE const*, int, int) [clone .isra.436] ()
#53 0x0000000000617555 in run_callback_immediate(VSCALLPTR*, int, VSARGTYPE const*, int, int) ()
#54 0x000000000088b9b7 in se_call_callback(filewindow_t*, VSCALLPTR*, int, int, VSARGTYPE const*, int) ()
#55 0x00000000006d27a3 in vs_execute_timer_event(int) ()
#56 0x00007fed5c9ebc03 in QObject::event(QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#57 0x00007fed5cd9886c in QWidget::event(QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#58 0x00007fed5cd49dac in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#59 0x00007fed5cd50523 in QApplication::notify(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#60 0x00007fed5c9d4a7d in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#61 0x00007fed5ca02958 in QTimerInfoList::activateTimers() () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#62 0x00007fed5c9ffe49 in idleTimerSourceDispatch(_GSource*, int (*)(void*), void*) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#63 0x00007fed548f8099 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#64 0x00007fed548f83f8 in g_main_context_iterate.isra.19 () from /lib64/libglib-2.0.so.0
#65 0x00007fed548f84ac in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#66 0x00007fed5ca00784 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#67 0x00007fed5cde5d66 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtGui.so.4
#68 0x00007fed5c9d324f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#69 0x00007fed5c9d3555 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#70 0x00007fed5c9d8599 in QCoreApplication::exec() () from /mounts/apps/linux/slickedit2023beta/bin/libQtCore.so.4
#71 0x00000000004d29ea in vmain(int, char**) ()
#72 0x0000000001ec7d59 in xmain ()
#73 0x000000000046e039 in main ()