**RemovedInPytest4Warnings are now errors by default.**

Following our plan to remove deprecated features with as little disruption as
possible, all warnings of type ``RemovedInPytest4Warnings`` now generate errors
instead of warning messages.

**The affected features will be effectively removed in pytest 4.1**, so please consult the
`Deprecations and Removals <https://docs.pytest.org/en/latest/deprecations.html>`__
section in the docs for directions on how to update existing code.

In the pytest ``4.0.X`` series, it is possible to change the errors back into warnings as a stop
gap measure by adding this to your ``pytest.ini`` file:

.. code-block:: ini

    [pytest]
    filterwarnings =
        ignore::pytest.RemovedInPytest4Warning

But this will stop working when pytest ``4.1`` is released.

**If you have concerns** about the removal of a specific feature, please add a
comment to `#4348 <https://github.com/pytest-dev/pytest/issues/4348>`__.