Comment 10 for bug 1932313

I suspect the remaining issues are related, and stem from how the breezy.testingplugins module is created in test_plugins.py BaseTestPlugins.setUp(). This is a dynamically created module established in that routine via:

        self.module = types.ModuleType(self.module_name)
 self.overrideAttr(plugin, "_MODULE_PREFIX", self.module_prefix)
 self.overrideAttr(breezy, "testingplugins", self.module)
 sys.modules[self.module_name] = self.module

I wonder if whatever caused the '.' import to fail maybe results in this dynamic creation to fail as well?

The machinery here (BaseTestPlugins.reset() in particular) is also munging things and adjusting caches, which may play into the odd caching behavior Christian mentions in LP: #1937173