staging test uses the /root/chromeos-admin, autotest  and ~/chromiumos checkouts for the sml task for test_push itself.
[1] To run test_push (out of /root/chromeos-admin).
[2] To obtain the list of servers to update
[3] To update all push servers (via deploy_server)

sml takes no pain to ensure that updated version of these repos are used.

For example, because [1] uses old code, any changes to the test_push task itself will not automatically get picked up in test_push. If this makes test_push fail before it can force a puppet run on the staging master (that updates /root/chromeos-admin checkout), we're stuck until hopefully the puppet cron job updates this checkout.

For example, because [2] uses old code, the fix for  issue 851538  was never automatically picked up. The list of servers to be updated was wrong, and so test_push failed early enough that it never updated the staging master itself.

For example, because [3] uses old code, the fix for issue 850118 was never automatically picked up. deploy_server kept failing until I manually updated the autotest checkout on staging master.