Primary branch name changed to "main" for all repos

Joe Kutner

As part of our commitment to being an inclusive and welcoming community, we've renamed the primary branch on all repos to "main".

Our Homebrew tap for Pack should continue to work. But if you're experiencing problems, please retap by running:

$ brew untap buildpacks/tap
$ brew tap buildpacks/tap
$ brew upgrade pack

Please let us know if you encounter any other issues.

The CNB team