I found the issue when moving from CentOS 6 -> 7. I don't know why we didn't see the issue on CentOS6 but it is probably due to placement of the global data in memory. In the CentOS6 build of the http_client (latest from master branch) we were lucky/unlucky to get a 0 in the memory just after the exported functions array when iterating in function find_mod_export_record.