apt locked files

If you tried to run apt update and you get this error, try the following.

$ apt update
E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) [duplicate]

Kill the process.

$ sudo killall apt apt-get

If that doesn’t work, remove the locked files.

$ sudo rm /var/lib/apt/lists/lock
$ sudo rm /var/cache/apt/archives/lock
$ sudo rm /var/lib/dpkg/lock*

Run apt update again.