Cherry-pick PR 4918 to master

[mradamcox]

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Description of Change

This is a cherry-pick of all the commits in #4918. Please see description in that PR.

Checklist

• Unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

I had to resolve some conflicts related to linting in packages.py.