Mod_python error: "PythonHandler mod_python.publisher"

Traceback (most recent call last):

  File "/usr/lib64/python2.4/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
    result = object(req)

  File "/usr/lib64/python2.4/site-packages/mod_python/publisher.py", line 213, in handler
    published = publish_object(req, object)

  File "/usr/lib64/python2.4/site-packages/mod_python/publisher.py", line 412, in publish_object
    return publish_object(req,util.apply_fs_data(object, req.form, req=req))

  File "/usr/lib64/python2.4/site-packages/mod_python/util.py", line 439, in apply_fs_data
    return object(**args)

  File "/soft/http/htdocs/MaKaC/categoryDisplay.py", line 32, in ical
    return categoryDisplay.RHCategoryToiCal( req ).process( params )

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/rh/base.py", line 379, in process
    DBMgr.getInstance().startRequest()

  File "/usr/lib/python2.4/site-packages/MaKaC/common/db.py", line 77, in getInstance
    cls._instance=DBMgr()

  File "/usr/lib/python2.4/site-packages/MaKaC/common/db.py", line 71, in __init__
    self._storage=ClientStorage(cfg.getDBConnectionParams(), username=cfg.getDBUserName(), password=cfg.getDBPassword(), realm=cfg.getDBRealm())

  File "build/lib.linux-x86_64-2.4/ZEO/ClientStorage.py", line 257, in __init__

  File "build/lib.linux-x86_64-2.4/ZEO/TransactionBuffer.py", line 57, in __init__

  File "/usr/lib64/python2.4/tempfile.py", line 459, in TemporaryFile
    dir = gettempdir()

  File "/usr/lib64/python2.4/tempfile.py", line 262, in gettempdir
    tempdir = _get_default_tempdir()

  File "/usr/lib64/python2.4/tempfile.py", line 208, in _get_default_tempdir
    raise IOError, (_errno.ENOENT,

IOError: [Errno 2] No usable temporary directory found in ['/tmp', '/var/tmp', '/usr/tmp', '/']