On older versions apparently upon child termination due to SIGINT
subprocess.poll() returned 1. On new python versions (such as 3.8.2),
-2 is returned, according to documentation:
A negative value -N indicates that the child was terminated by signal N (Unix only).
Let's catch the SIGINT in the child process and exit with a known 42
value to fix different behavior.
Change-Id: I7949ff2b435e91e890061e6840b0f411f8b0a817
Pau Espin
Neels Hofmeyr