In general, tests are also allowed to access the internet. As this
usually makes tests less reliable, this should be kept to a minimum; but
for many packages their main purpose is to interact with remote web
services and thus their testing should actually cover those too, to
ensure that the distribution package keeps working with their
corresponding web service.
Debian's production CI infrastructure allows unrestricted network
access, in Ubuntu's infrastructure access to sites other than
`*.
ubuntu.com` and `*.
launchpad.net` happens via a proxy (limited to
DNS and http/https).