if yarn v2+ is globally then prefer npm or recommend to downgrade to yarn classic globally

[saihaj]

Yarn 2+ has a different way to how they hoist modules but also not ideal to have those installed globally installed . From Yarn docs:

The preferred way to manage Yarn is by-project and through Corepack, a tool shipped by default with Node.js. Modern releases of Yarn aren't meant to be installed globally, or from npm.
So going to yarn classic aka yarn@v1 globally solves the issue or simply using npm fixes the issue.
https://yarnpkg.com/getting-started/install

We can improve the CLI if globally yarn installed is not classic prefer npm or if npm somehow is not globally available recommend to downgrade to yarn classic to reduce confusion.

Another thing I am thinking, breaking change but by default avoid doing install and instead user provides a flag on what package manager they want to use.

Related

• allow users to choose package manager #1085
• part of init make git disabled by defualt #1532