Comment 6 for bug 516032

Just a note - if you change "https_proxy" and then run "sudo whatever" - the changed environment variable won't be inherited by the sudo command.
So to get anywhere with this I had to do this as root:
  $ sudo bash
  # export https_proxy=http://www.example.com:8000/
  # add-apt-repository ppa:<whatever>
(just a note in case anyone else got messed up by this - this workaround still doesn't fetch gpg keys, but at least it updates your apt sources)