Yarn 4.x now supported on Heroku

Change effective on 03 November 2023

Yarn 4 has recently been released and introduces new functionality and features as documented in the Yarn 4.0 release announcement. This new version is now available for use on Heroku.

To upgrade an app already using Yarn Modern release (2.x or 3.x), run yarn set version stable.

To upgrade an app using Yarn Classic, see our upgrade guide.