[e12e]

It's more than that. It broke working projects because v2 was opt-out, not opt-in.

If they'd made a new tool/project called "yarn2", leaving "yarn" alone, that would've been fine.

[ojkelly]

It’s opt-in though?

You install it into your repository, and it gets vendored.

The yarn 1 binary on your machine will use yarn 2/3 if it’s in the repo, otherwise it will just run yarn 1 as normal.