It seems the 15 seconds the script run-buildbot-test.py waits for the master to be started (and the database upgraded) is not enough if the system has a rotational HDD-
Let's raise it to 60.
Created attachment 332960 [details]
Comment on attachment 332960 [details]
Clearing flags on attachment: 332960
Committed r228005: <https://trac.webkit.org/changeset/228005>
All reviewed patches have been landed. Closing bug.