This is an alternative to D516. It drops the 'all' subcommand
entirely and adds some capabilities to 'compose' to make it
suitable for scripting. --ifnotcurrent will check if the compose
is the same as the current validation event, and bail out if it
is. --wait waits for the compose to be available. I've also
enhanced fedfind (in 1.4.1) to allow passing just 'Branched'
as the milestone; it will guess the release and date, now (it
didn't before).
With all of that taken together, we could have three cron jobs,
one for 'current', one for 'branched', and one for 'rawhide'.
That way we don't have to do any clever multiprocess/round-robin
waiting stuff, and the jobs for each release will be run and
reported as fast as possible (and we can run the compose report
right after the trigger script and have that sent out
efficiently too).