Please include errno when raising LockError

[nutjob]

I've been getting intermittent startup errors on a Zope instance from zc.lockfile 1.0.0, zc/lockfile/__init__.py line 57, in the call to fcntl. The message is displayed as "LockError: Couldn't lock FILENAME".

Unfortunately, there's no further information, as the try block catches the IOError and raises a fresh LockError.

That IOError does have a useful bit of data, though: the errno value left by the failed call to fcntl. With that, I'd have a clue as to what the underlying issue is.

Perhaps the errno could be included in the raised LockError's message, as suggested by the patch.

Thanks,
Sean "nutjob" Kelly.