hook: have a generic hook for transaction opening We are adding generic hooking for all transactions. We do not really have any useful information to include when opening the transaction but this is a useful time to allow a hook anyway. We better let people abort transaction before they happen than after multiple seconds/minutes of processing.

#!/usr/bin/env python

import errno, os, sys

for f in sys.argv[1:]:
    try:
        print f, '->', os.readlink(f)
    except OSError, err:
        if err.errno != errno.EINVAL:
            raise
        print f, 'not a symlink'

sys.exit(0)