post-lock — 成功锁定路径的通知。
The post-lock hook runs after one or
more paths has been locked. It is typically used to send
email notification of the lock event.
If the post-lock hook returns a
nonzero exit status, the lock will
not be aborted since it has already
completed. However, anything that the hook printed
to STDERR will be marshalled back to the
client, making it easier to diagnose hook failures.