Running github actions locally

If you'd like to run the same integration tests we run on github but on your own machine, you can do the following.

Install homebrew per https://brew.sh/
Install https://github.com/nektos/act with "brew install act"
cd into meshtastic-device and run "act"
Select a "medium" sized image
Alas - this "act" build almost works, but fails because it can't find lib/nanopb/include/pb.h! So someone (you the reader? @geeksville ays hopefully...) needs to fix that before these instructions are complete.