s390 test failure: file descriptor cannot be a negative integer
full log https://buildd.debian.org/status/fetch.php?pkg=pandas&arch=s390x&ver=0.13.0-2&stamp=1390095775&file=log

```
======================================================================
ERROR: test_flush (pandas.io.tests.test_pytables.TestHDFStore)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/«PKGBUILDDIR»/debian/tmp/usr/lib/python2.7/dist-packages/pandas/io/tests/test_pytables.py", line 523, in test_flush
    store.flush(fsync=True)
  File "/«PKGBUILDDIR»/debian/tmp/usr/lib/python2.7/dist-packages/pandas/io/pytables.py", line 571, in flush
    os.fsync(self._handle.fileno())
ValueError: file descriptor cannot be a negative integer (-1)
```

may be due to a recent update to pytables 3.0.0-2
