The 'Unix Signals' (https://en.wikipedia.org/wiki/Unix_signal#Handling_signals) wiki explains that: > 'There are two signals which cannot be intercepted and handled: SIGKILL and SIGSTOP.' Signed-off-by: kevinmeredith <kevin.m.meredith@gmail.com> Upstream-commit: ef7cd217663c7f6bff5f1d49461c004e86fed867 Component: engine