Tests in Layers inheriting from UnitTestLayer are not executed as unit tests

[Christian Theune]

It is questionable (but should be discussed) whether this scenario is by accident or on purpose.

[Tres Seaver (tseaver)]

AFAICT, it should be an error to ever mix layers into unit tests at all:
 the whole distinction between "unit" and "functional" tests is that unit
tests don't need (or want) the shared setup provided by layers.

I've heard an argument that layers are useful for "grouping" tests together
logically, orthagonally to the main purpose of layers, which is to drive the
shared setup machinery. If this argument ever had much weight, I think
it does no longer, now that we have exploded the monolithic Zope3 tree
into smaller, more focused projects.

I'm marking this as incomplete because I think it should be "wontfix",
but don't want to do that abruptly: those who are sure that I'm wrong
get sixty days to reset the status.

I could easily be persuaded that the whole existence of UnitTestLayer
is an "attractive nuisance."

[Colin Watson (cjwatson)]

The zope.testing project on Launchpad has been archived at the request of the Zope developers (see https://answers.launchpad.net/launchpad/+question/683589 and https://answers.launchpad.net/launchpad/+question/685285). If this bug is still relevant, please refile it at https://github.com/zopefoundation/zope.testing.