Implement RFC 0014: Enable Support for Yarn Berry

[thitch97]

Context

RFC
Exploration

This buildpack should be re-written such that it supports a codepath for installing application dependencies using Yarn Berry.

Details

• API: The buildpack should require node and yarn during build and should provide either node_modules OR yarn_pkgs.

• The logic for installing dependencies with Yarn Classic should be kept as separate as possible from that of Yarn Berry; preferably as separate packages.

Acceptance Criteria

Given an application which uses Yarn Berry to manage its dependencies:

• when pack build is run with the yarn-install buildpack, it should pass detection and build successfully.
• The required dependencies should be installed in the resulting container.

[jwhitcraft]

Any update on this?

[loewenstein-sap]

I am wondering as well, what the state of this is. It looks pretty old and the PR looks devastatingly large. @thitch97 are you actively working on this?