One package manager enforcement on Node.js builds

Change effective on 23 September 2024

Heroku’s Node.js Buildpack supports choosing one of three package managers for performing builds: npm, pnpm, or Yarn. To ensure that your apps build using the correct package manager, we now detect when multiple package managers are specified in package.json. If multiple package managers are detected this will fail the build.

For more information please see our article on Node.js Support.