Yeah we have this particular problem, a Python program written in Python2 as late as 2014 for RHEL6, using Cython extensions. It compiles and packages fine for RHEL7, but when I run it on it just crashes upon receving a UDP packet from the network.

The original programmer is long gone, and I while I am a semi-competent Python scripter and a slightly above average C programmer, I'm not looking forward to having to dig deep into this code, and patch it up to keep running.