Could not get lock /var/lib/dpkg/lock-frontend

E: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 3076 (unattended-upgr)

解决办法：

sudo rm /var/lib/apt/lists/lock


sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

参考：

https://unix.stackexchange.com/questions/374748/ubuntu-update-error-waiting-for-unattended-upgr-to-exit