Bug#893397: adapt the cron scripts to use http:// instead of ftp://

On Tue, Mar 20, 2018 at 10:55 PM, Osamu Aoki wrote:

> apt-get has -C option to use non-standard /etc/apt/sources.list
> listing unstable distribution:

This is the wrong way to completely override the system apt
configuration. The right way is to set the APT_CONFIG environment
variable. See the apt.conf(5) manual page, APT_CONFIG is the first
method that apt uses to find the config file and the -C command-line
option is the very last one so it cannot prevent loading all the
system config. The chdist tool (from devscripts), the apt-venv package
and the derivatives census code get this correct.

I definitely agree that apt-get could be used to download packages
from repositories, especially since it will verify hashes and
signatures.