https://bugs.openldap.org/show_bug.cgi?id=10099
--- Comment #7 from AllenM amcwongahey@rbbn.com --- The process which uses openLDAP does absolutely nothing special and does not even interact with the Kernel. When that openLDAP function is called it simply never returns back from the OpenLDAP API.
I am not able to get a kill -6 to generate a CORE file. Not able to get anything useful from strace either.
I provided the unified DIFF file which added back in the compile flags which were present prior to OpenLDAP 2.5 and that resolved the entire issue. No more hangs and it functionally works just fine now just like it always has before.
If I call an OpenLDAP API function and it never comes back to the calling process it is clear it is hanging inside OpenLDAP.
I added quite a bit of debug in OpenLDAP and I could even prove to myself from doing that that it was getting stuck.