Launchpad does not have a sensible unittest framework

WebserverHelper (in lib/canonical/launchpad/scripts/tests/webserver_helper.py) inherits from importd.tests.helpers.SandboxHelper. There are a few problems with this.

SandboxHelper always uses the same sandbox directory: ",,job_test". Tests ought to be independent from each other, even if a previous test didn't run its tearDown because it failed. A much better approach would be make and use a new temporary directory each time (and with a directory name that is more helpful than ",,job_test").

Also, SandboxHelper mucks with os.environ['HOME'], which is important for some tests, but irrelevant for most. It certainly is irrelevant to WebserverHelper.

Finally, canonical.launchpad.scripts.tests depending on importd.tests not a good dependency, I think. We ought to have infrastructure like this in a sensible place, rather than in a random module (or just as bad re-done ad hoc, like the tempdir thing is done in various places throughout the test suite).