could not get lock /var/lib/dpkg/lock-frontend. it is held by process (unattended-upgr) code example
Example 1: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)
Method 1
ps aux | grep -i apt
sudo kill -9 <process_id>
Method 2
sudo lsof /var/lib/dpkg/lock
sudo lsof /var/lib/apt/lists/lock
sudo lsof /var/cache/apt/archives/lock
sudo kill -9 <process_id>
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock
sudo dpkg --configure -a
sudo apt update
Example 2: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
ps aux | grep -i dpkg
// Kill processes which are running
sudo kill -9 <pid>
// Restart the accounts daemon
sudo systemctl restart accounts-daemon
Example 3: E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?
ps aux | grep -i apt
sudo kill <process_id>
sudo kill -9 <process_id>
sudo killall apt apt-get
Example 4: E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)
sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock