Source packages appropriate by default?

[Robie Basak]

Another idea about mechanism:

It seems to me that "apt-get update" does two logical tasks which serve
two different use cases for many users, one of which is rare and
often unnecessary.

How about an apt configuration option that, when enabled (default: off),
disables source index downloads when "apt-get update" is not used with
an additional argument like "apt-get --include-source update"? Or just
"apt-get update-sources"?

A subsequent "apt-get source" could then warn you, in the error message
that no sources are defined, that the configuration option to disable
source index downloads is set, and the correct command to override it.

Caveat 1: users who want to enable sources all the time would then need
to edit (and know to edit) /etc/apt/apt.conf.d/10sources or something.

Caveat 2: what other tools need to modified to honour this? Is it too
onerous to patch them all?

Just a thought. Removing or manipulating deb-src lines does seem
easier.