I tried to update the apt cache on a machine that had not been updated in a long time:
$ sudo apt-get update
But that got stuck at one of the repositories Waiting for headers. No matter how many times I tried the command, it would get stuck at this.
The problem went away once I cleared the cache using these steps as explained here:
$ sudo apt-get clean $ cd /var/lib/apt $ sudo mv lists lists.old $ sudo mkdir -p lists/partial $ sudo apt-get clean $ sudo apt-get update
Tried with: Ubuntu 16.04