+Currently, all pytests must be located in either test/ext or test/int.
+Internal test filenames must match test_*.py, and external tests must
+be located in text/ext and their filenames must match test-* (see
+test/ext/conftest.py for the handling of the latter). Any paths
+matching those criteria will be automatically collected by pytest.
+
+Some aspects of the environment are automatically restored after each
+test via fixtures in conftest.py, including the state of the
+environment variables and the working directory; the latter is reset
+to the top of the source tree.