How to find memory leak in c++ UDx

Hi,
One of my UDx show signs of memory leak, rss /vsz is monotonically increasing for vertica-udx-C++ process as it runs.
Yes it does run in fenced mode.
Code reviews does not point to smoking gun.
Any hints, advices?
Please do not mention use of vt_alloc.
Best advice would be instructions how to run ASAN on UDx in fenced mode.