I made this affect juju also, as where this bug was filed juju explicitly declared:
$ sudo grep apt_mirror /var/lib/cloud/instance/cloud-config.txt apt_mirror: '' -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1621180 Title: specifying apt_mirror of '' renders empty entries in /etc/apt/sources.list for uri To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-init/+bug/1621180/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs