--lf has an optimization where it skips collecting Modules (python
files) which don't contain failing tests. The optimization works by
getting the paths of all cached failed tests and skipping the collection
of Modules whose path is not included in that list.
In pytest, Package nodes are Module nodes with the fspath being the file
`<package dir>/__init__.py`. Since it's a Module the logic above
triggered for it, and because it's an `__init__.py` file which is
unlikely to have any failing tests in it, it is skipped, which causes
its entire directory to be skipped, including any Modules inside it with
failing tests.
Fix by special-casing Packages to never filter. This means entire
Packages are never filtered, the Modules themselves are always checked.
It is reasonable to consider an optimization which does filter entire
packages bases on parent paths etc. but this wouldn't actually save any
real work so is really not worth it.
Ran Benita