Prework

• Read and agree to the code of conduct and contributing guidelines.
• If there is already a relevant issue, whether open or closed, comment on the existing thread instead of posting a new issue.
• New features take time and effort to create, and they take even more effort to maintain. So if the purpose of the feature is to resolve a struggle you are encountering personally, please consider first posting a "trouble" or "other" issue so we can discuss your use case and search for existing solutions first.
• Format your code according to the tidyverse style guide.

Proposal

I need to think more about this because it breaks one of the guardrails: do not depend stuff in memory that vanishes when you restart R. But several people have asked for this, and it would make it easier to manage multiple sub-projects in the same directory. (I am more willing to accept that people are going to try to write sub-projects, so instead of trying to convince folks otherwise, it would be better to establish patterns to do this safely.)