解决apt-get /var/lib/dpkg/lock-frontend 问题

运行 apt-get 时报如下错
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?
解决方案:

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

都运行一遍，具体也不知道哪条起了作用。