[deklerk]

Others have answered this better than I, but I'll tell you what I've seen:

- grpc-go and gopls had great "Contributors welcome" issues set up. For both of them, I had to email/chat various people for help getting used to the code, but everyone was extremely pleasant and helpful (and happy to help). - Drive treated it like an internship, where a TL curated a set of low-priority issues and I just went and chatted with folks when I had questions. Again, everyone was very helpful. - Other Go tools I've worked on have had really intuitive codebases, or were quite small, and have been easy to dive right in. That's helpful too, though I do end up chatting with people a lot.

If I had to make a general statement I guess I would say: don't allow 20%ers if you don't have the time for an intern. Treat the 20% like an internship: free labour with a little bit of extra onboarding. It's ok to not have that time, but I think most people are usually happy and excited to provide that help! =)

Oh, actual tip: having a myproject-users@ / myproject-devs@ mailing list, or a #myproject-devs chat channel, goes a long way. Then, chatting and asking questions can be informal and ad-hoc.