As discussed in this PR there are some issues with the current pin-set for
layer-basic. In essence, deploying a charm with dependencies built at deploy time currently fails on Python 3.7 systems.
A solution to the issue is to unpin
setuptools which allows a compatible combination of those tools to be distributed with the charm.
However this also mandates a change of the default value for the
include_system_packages configuration option in
Without this change a charm being deployed will end up using incompatible
setuptools versions from what is installed on the system and subsequently fail.
Having the charms rely on their distributed dependencies only, without interference from system installed packages, is a safer default. It also prohibits charm authors from inadvertently making boundary violations by having the charm rely on the software it is installing or managing on a system.
Most charms should be OK with this change, and charm authors still have the option to explicitly set
True to restore the old default behaviour.