I have forgotten why this one is not used any longer:

```
(sid)root@vagus:/home/yoh/deb/gits/pkg-exppsy/pandas# git grep KnownFailure
pandas/util/decorators.py:class KnownFailureTest(Exception):
pandas/util/decorators.py:    Make function raise KnownFailureTest exception if given condition is true.
pandas/util/decorators.py:        Message to give on raising a KnownFailureTest exception.
pandas/util/decorators.py:                raise KnownFailureTest(msg)
```

but also look e.g. at https://github.com/numpy/numpy/blob/master/doc/TESTS.rst.txt#known-failures-skipping-tests