AttributeError: 'NoneType' object has no attribute 'rollback'

[vladsynkov@…]

I'm getting following error while trying to upgrade my DB.

That's happend after installing ​TH:ComponentDependencyPlugin

Traceback is:

2010-06-29 15:02:07,642 Trac[console] ERROR: Exception in trac-admin command: 
Traceback (most recent call last):
  File "build/bdist.linux-i686/egg/trac/admin/console.py", line 107, in onecmd
    rv = cmd.Cmd.onecmd(self, line) or 0
  File "/usr/lib/python2.6/cmd.py", line 218, in onecmd
    return self.default(line)
  File "build/bdist.linux-i686/egg/trac/admin/console.py", line 257, in default
    return cmd_mgr.execute_command(*args)
  File "build/bdist.linux-i686/egg/trac/admin/api.py", line 123, in execute_command
    return f(*fargs)
  File "build/bdist.linux-i686/egg/trac/env.py", line 790, in _do_upgrade
    self.env.upgrade(backup=no_backup is None)
  File "build/bdist.linux-i686/egg/trac/env.py", line 533, in upgrade
    with_transaction(self)(participant.upgrade_environment)
  File "build/bdist.linux-i686/egg/trac/db/api.py", line 82, in transaction_wrapper
    ldb.rollback()
  File "build/bdist.linux-i686/egg/trac/db/util.py", line 102, in __getattr__
    return getattr(self.cnx, name)
AttributeError: 'NoneType' object has no attribute 'rollback'

[Christian Boos]

Interesting. I forgot to do one change after r9442:

trac/db/api.py

@@ -72 +72 @@
         elif ldb:
             fn(ldb)
         else:
-            ldb = _transaction_local.db = env.get_db_cnx()
+            ldb = _transaction_local.db = DatabaseManager(env).get_connection()
             try:
                 fn(ldb)
                 ldb.commit()

However, this omission should have been harmless. Need to investigate further.

[anonymous]

I can not get my trac working becouse of this bug. What should I do?

[Christian Boos]

Which Python version are you using?

[anonymous]

Python 2.6

[Christian Boos]

I can reproduce the problem if I do an explicit db.close() from within an upgrade_environment(self, db) method, which normally shouldn't happen.

The plugin in question doesn't even use db in that method. Are you using some other plugins?

[anonymous]

Yes, I'm using TracHoursPlugin with all it's dependences (feedparser-4.1, python-dateutil-1.4.1, SilverCity-0.9.7, tracsqlhelper, TicketSidebarProviderPlugin)

[anonymous]

Acually I've installed ​TH:ComponentDependencyPlugin to get work ​TH:TracHoursPlugin. And SetupTracHours component of TracHoursPlugin require DB upgrade.

2010-06-29 15:02:07,629 Trac[env] WARNING: Component <trachours.setup.SetupTracHours object at 0xabe302c> requires environment upgrade

[Christian Boos]

Looks like this was caused by ​TH:TracSqlHelper, see ​#TH7262.

[Remy Blank]

Are you still going to apply the patch from comment:1?

[Christian Boos]

I'd like to, but as is, it breaks the tests.

[Christian Boos]

Replying to cboos:

I'd like to, but as is, it breaks the tests.

Because the tests rely on re-using a single global DatabaseManager, regardless of the actual environment used, so one possible fix would be to preset the per environment DatabaseManager instance to this global one… Not sure it's worth the additional complexity in EnvironmentStub.