=========================
Bug Fixes
---------
- `5031 <https://github.com/pytest-dev/pytest/issues/5031>`_: Environment variables are properly restored when using pytester's ``testdir`` fixture.
- `5039 <https://github.com/pytest-dev/pytest/issues/5039>`_: Fix regression with ``--pdbcls``, which stopped working with local modules in 4.0.0.
- `5092 <https://github.com/pytest-dev/pytest/issues/5092>`_: Produce a warning when unknown keywords are passed to ``pytest.param(...)``.
- `5098 <https://github.com/pytest-dev/pytest/issues/5098>`_: Invalidate import caches with ``monkeypatch.syspath_prepend``, which is required with namespace packages being used.