Trying the demo in an NFS directory (we use NetApps for
all our mass storage) causes an error because flock()
fails. Traceback from portalocker line 124 in lock says
"IOError: [Errno 37] No locks available".  Easy to
reproduce with:

$ python portalocker.py
Traceback (most recent call last):
  File "portalocker.py", line 136, in ?
    portalocker.lock(log, portalocker.LOCK_EX)
  File
"/tmp_mnt/home/moraes/roundup-0.7.8/roundup/backends/portalocker.py",
line 124, in lock
    fcntl.flock(file.fileno(), flags)
IOError: [Errno 37] No locks available
Exit 1

Switching to lockf() works fine (tested on Red
Enterprise 3 Linux, Python 2.3.4) and Solaris 8/Sparc
(also Python 2.3.4).
With the attached patch, users of portalocker can switch
from lockf to flock by setting portalocker.lockmethod =
fcntl.flock.

Regards,
Mark.