yum is run at each cf-promises, having a massive perf cost, on redhat-like system
On redhat like system, at each cf-promises (but also at each cf-server restart), we run the command
LANG=C /usr/bin/yum --setopt=exit_on_lock=True 2>&1 | /bin/grep -q -E '(Command line error: no such option: --setopt|Main config did not have a exit_on_lock attr. before setopt)'
it goes without saying that it has a huge perf cost (0,5 s CPU on a test platform, about a third of total cf-promises run)
we could guard the execution by a simple "agent" class, and have easy gain