[Buildbot] #2991: Confusing error message when the database is missing or empty

[Buildbot trac]

#2991: Confusing error message when the database is missing or empty
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Reporter:  sa2ajj     |       Owner:
    Type:  undecided  |      Status:  new
Priority:  major      |   Milestone:  undecided
 Version:  0.8.9      |  Resolution:
Keywords:             |
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Comment (by Ben):

 I don't believe we can do much about that.

 This situation occurs because the user deleted the sqlite db from the
 buildbot directory. Buildbot doesn't expects the database not to be there
 when the master.cfg is there, hence doesn't care about checking for its
 presence (which is highly DB-backend dependent !).

 the user brought an inconsistent state in the buildbot directory, and
 expected buildbot to fix it itself.

 Note that a 'upgrade-master' is enough to fix the situation, not (as in
 this ticket) a start + upgrade-master, as the start will try to start,
 complains about the db in an inconsistent state, and refer to the upgrade-
 master command. In the meantime, the sqlite db have been created, and is
 confusing the upgrade-master command which will exit with the following
 error:

 {{{
 sqlalchemy.exc.OperationalError: (OperationalError) disk I/O error 'PRAGMA
 table_info("migrate_version")' ()
 }}}

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Ticket URL: <http://trac.buildbot.net/ticket/2991#comment:1>
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