The python CommandExecutorHandler class calls the python generated activate_this.py script before executing a given requested python script, in order to establish the python virtual env context. After many, many calls, all request failed with a message stating "/bin/sh : Argument list too long", The actual error was the PATH variable building up to be too big, preventing any child process to be started.

The fix itself was quite simple, removing duplicates from the PATH env var, after each call to this script.