rein@OpenLDAP.org writes:

If this is actually true, and if so why the lock and/or destroy calls didn't fail beats me...

If you mean mutex locks, maybe they did. OpenLDAP code generally doesn't check ldap_pvt_thread_*() for error return:-(

You can turn on assert(success) inside these calls with

./configure CPPFLAGS='-DLDAP_THREAD_DEBUG=2 -D_GNU_SOURCE' make -s LDAP_THREAD_DEBUG=nocount nice make test

_GNU_SOURCE is for Linux. But there might be some assert crashes during shutdown after failure, in particular in slap tools.