No connector loaded for postgres schema

[ryan.g.steele@…]

First, some pre-requisite information:

The command I'm using is:

./sqlite2pg.py -e /path/to/trac -p 'postgres://user:pass@localhost:5432/trac'

The stack trace I'm getting is:

Traceback (most recent call last):
  File "./sqlite2pg.py", line 335, in <module>
    sys.exit(main(sys.argv[1:]))
  File "./sqlite2pg.py", line 331, in main
    Main(opts)
  File "./sqlite2pg.py", line 244, in Main
    pgenv = getPostgreSQLEnvironment(opts)
  File "./sqlite2pg.py", line 209, in getPostgreSQLEnvironment
    cnx = env.get_db_cnx()
  File "/usr/lib/python2.6/dist-packages/trac/env.py", line 285, in
get_db_cnx
    return DatabaseManager(self).get_connection()
  File "/usr/lib/python2.6/dist-packages/trac/db/api.py", line 90, in
get_connection
    connector, args = self._get_connector()
  File "/usr/lib/python2.6/dist-packages/trac/db/api.py", line 131, in
_get_connector
    raise TracError('Unsupported database type "%s"' % scheme)
trac.core.TracError: Unsupported database type "postgres"

The sys.path is:

['/root', '/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2',
'/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old',
'/usr/lib/python2.6/lib-dynload', '/usr/lib/python2.6/dist-packages',
'/usr/lib/python2.6/dist-packages/PIL', '/usr/lib/pymodules/python2.6',
'/usr/lib/pymodules/python2.6/gtk-2.0', '/usr/local/lib/python2.6/dist-packages']

The relevant modules are located in the sys.path path:

/usr/lib/python2.6/dist-packages/psycopg2
/usr/lib/python2.6/dist-packages/trac
/usr/lib/python2.6/dist-packages/trac/db/postgres_backend.py
/usr/lib/python2.6/dist-packages/trac/db/sqlite_backend.py

Debugging output shows that the script finds psycopg2, but doesn't load the PG connector:

has_psycopg: True
scheme: postgres
connectors: [<trac.db.sqlite_backend.SQLiteConnector object at 0x1c12b10>]
candidates: []

And, that's the reason the script fails, and the reason I've filed this ticket. The 'postgres' schema doesn't match any in the candidates list. I truly don't believe this is a path issue, given the information above. A thread I started on the trac-users mailing list can be found archived here, in case it helps to fill in any gaps: ​http://www.gossamer-threads.com/lists/trac/users/48799

Cheers, Ryan

[ryan.g.steele@…]

FYI, this is with Trac 0.11.7, and the latest version of sqlite2pg (0.10)

[anonymous]

I discovered the problem today, and hopefully this can benefit others having similar problems. In my trac.ini, the following parameter was set:

trac.db.postgres_backend.postgresqlconnector = disabled

I'm not sure that's even required when using non-Postgres backend (the MySQL connector was disabled as well), but for some reason it was in there. I hadn't thought to look in trac.ini for this particular issue for two reasons: first, the existing installation only needed the SQLite connector, so it didn't seem intuitive to assume that sqlite2pg would use trac.ini to determine the validity of other connectors (that's what sqlite2pg's connection string argument is for); additionally, I could find no documentation that indicated modifications to trac.ini were relevant, let alone necessary, until after the backend conversion had completed (i.e., changing the database connection string from sqlite to postgres to begin using the PG backend).

Given this turn of events, I believe the ticket can be closed. However, I think it underscores the benefits of documenting these types of blocking dependencies on trac.ini in the sqlite2pg documentation/help option, which is something I'd be happy to do if patches to the script and/or documentation will be accepted.

[Ryan J Ollos]

This plugin is deprecated. See the TracMigratePlugin.