Incorrect unmet peer dependency warning

[betalb]

Do you want to request a feature or report a bug?

Bug

What is the current behavior?
Yarn may warn about unmet peer dependencies even if they are installed

If the current behavior is a bug, please provide the steps to reproduce.

• Install a set of packages that are triggering issueyarn add babel-core babel-loader webpack babel-cli
• Install some dummy package yarn add peter
• Check that yarn prints warning about unmet peer dependency: warning " > babel-loader@7.1.2" has unmet peer dependency "babel-core@6 || 7 || ^7.0.0-alpha || ^7.0.0-beta || ^7.0.0-rc".

Attaching generated yarn.lock & package.json

• yarn.lock.txt
• package.json.txt

Without babel-cli issue is not showing up

What is the expected behavior?
No warnings about unmet peer dependencies should be printed, because bable-core is installed, and has version 6.26.0

Please mention your node.js, yarn and operating system version.
node: v8.9.0
yarn: 1.3.2
os: macOS 10.13.1

[betalb]

Example was inspired by issue #4589 (comment)

[rally25rs]

Duplicate #4743

Yarn isn't noticing when the peer dep is a direct dep from package.json. A fix is being worked on...