Comment 2 for bug 1626775

My Ubuntu 16.04 system does not have a default gateway.  Instead, I have configured apt-get to use an HTTP proxy.

Today I tried to add a ppa.

$ sudo add-apt-repository ppa:libreoffice/libreoffice-prereleases
Cannot add PPA: 'ppa:~libreoffice/ubuntu/libreoffice-prereleases'.
ERROR: '~libreoffice' user or team does not exist.

The error message is incorrect.  ~libreoffice does exist.

A better error message would be something like:

ERROR: unable to connect to remote host <hostname>

To reproduce the problem, simply run "sudo route del default", and then try to add a new ppa with add-apt-repository.

Bugs #1053531, #1433761 may be tangentially related.