We support all of those already, except maybe the "123,456".

I'd never even heard of -g "123 456" until I wrote the new command. I'd prefer to remove it since it's a weird syntax, but there seem to be a lot of people using it.

-g 123 -g 456 does not work.

Here's the unittest that confirms a variety of related behaviors:

https://cs.corp.google.com/chromeos_public/chromite/cli/cros/cros_tryjob_unittest.py?rcl=c568d842e8ab908a2e8a1e5fcb4d5fa88e1b9880&l=63

Here's an example build spawned with cros tryjob -g 744284 -g 742205 cyan-no-vmtest-pre-cq cyan-paladin
https://uberchromegw.corp.google.com/i/chromiumos.tryserver/builders/paladin/builds/4141

Here's the real world test which shows otherwise:
➜ cros tryjob -g 744284 -g 742205 cyan-no-vmtest-pre-cq cyan-paladin
Verifying patches...
Submitting tryjob...
Successfully sent PUT request to [buildbucket_bucket:master.chromiumos.tryserver] with [config:cyan-no-vmtest-pre-cq] [buildbucket_id:8964288791307500512].
Successfully sent PUT request to [buildbucket_bucket:master.chromiumos.tryserver] with [config:cyan-paladin] [buildbucket_id:8964288791018213168].
Tryjob submitted!
To view your tryjobs, visit:
  https://uberchromegw.corp.google.com/i/chromiumos.tryserver/waterfall?committer=davidriley@chromium.org&builder=no_vmtest_pre_cq&builder=paladin

Sigh, I'm an idiot.  Too many invocations and matched the wrong build.

I dislike the way we group tryjobs today. It's awkward and painful. The only good news is that we have a plan to fix it. It's just currently blocked on CrOps.

I've been talking about them to try and get it prioritized. Working on an email to collected assorted discussions together right now.