======  Existing lock file /etc/gshadow.lock without a PID ======
Error 
<code>
groupdel: existing lock file /etc/gshadow.lock without a PID
groupdel: cannot lock /etc/gshadow; try again later.
</code>

solusi
<code>
sudo rm /etc/passwd.lock
sudo rm /etc/shadow.lock
sudo rm /etc/group.lock
sudo rm /etc/gshadow.lock
sudo rm /etc/subgid.lock
sudo rm /etc/subuid.lock
</code>