add-apt-repository strangely adds in ubuntu

[Brian Murray]

bdmurray@flash:~$ sudo add-apt-repository ppa:graphics-drivers/ppa
[sudo] password for bdmurray:
Cannot add PPA: 'ppa:~graphics-drivers/ubuntu/ppa'.
The team named '~graphics-drivers' has no PPA named 'ubuntu/ppa'
Please choose from the following available PPAs:
 * 'ppa': Proprietary GPU Drivers

Notice how the first command was missing a ~ and while that got added so did "/ubuntu/". Manually, adding in the ~ and the command worked.

bdmurray@flash:~$ sudo add-apt-repository ppa:~graphics-drivers/ppa
 Fresh drivers from upstream, currently shipping Nvidia.
 ...

This was on Ubuntu 16.04 with:

bdmurray@flash:~$ apt-cache policy software-properties-common
software-properties-common:
  Installed: 0.96.20.4
  Candidate: 0.96.20.4
  Version table:
 *** 0.96.20.4 100
        100 /var/lib/dpkg/status