if isinstance(err, twisted.python.failure.Failure):
err = err.getTraceback()
print('%s[%#x] %s' % (cl.desc, id(req), err.strip('\n').replace('\n',' / ')),
if isinstance(err, twisted.python.failure.Failure):
err = err.getTraceback()
print('%s[%#x] %s' % (cl.desc, id(req), err.strip('\n').replace('\n',' / ')),