Anything, as long as it has < 100 google results. At least, plonk the project name into the github search, and see if there are existing projects using exactly

Anything, as long as it has < 100 google results. At least, plonk the project name into the github search, and see if there are existing projects using exactly that name. I found at least EIGHT other projects with more then 100 stars already named "carbon". At least one of them is VERY widely used (carbon, which is the time-series backend for graphite). Basically, you're actively making life harder for users when you decide to name-collide with existing active projects.