The nearest package directory doesn't seem to be part of the project

Description

We have a monorepo with a package.json in the root that lists the workspaces:

"workspaces": [
	"packages/core/*",
	"packages/react/*",
],

I wanted to upgrade our version of Yarn so I removed all node_modules and our yarn.lock in root and tried yarn after the upgrade but got the following error:

Usage Error: The nearest package directory ({path}) doesn't seem to be part of the project declared in {path}.

This used to work fine with .yarn/releases/yarn-berry.js but not with .yarn/releases/yarn-2.4.0.cjs.

Solution

I created an empty yarn.lock in the root and tried yarn again and everything worked.

This was all a bit unintuitive. I’m not sure if maybe the error should suggest that as a solution or if it should just create one for me(?) but thought I’d raise for discussion.

[merceyz]

The error happens when you have a yarn.lock (or package.json) file higher up in the filetree, at that point Yarn thinks you’re in a workspace you haven’t declared and throws.

[larixer]

Maybe clearer expression of my idea is: Yarn 2 tries to exercise control outside of the current project upwards, without boundaries, I think it is not right. Yarn should exercise control inside project boundaries and it should not bother Yarn what is upwards in directory hierarchy, if there is yarn.lock, package.json or anything else upwards in the directory hierarchy. In order to exercise control within project boundaries Yarn should not miss real project boundary and go upwards past it, how to do it right is a separate question.