[Bug] Yarn 2 should run child processes with the same Node

[segrey]

• I'd be willing to implement a fix

Describe the bug

Actual: Yarn 2 uses node from PATH when executing yarn node ...
Expected: Yarn 2 should use the Node that is running Yarn itself when executing yarn node ...

To Reproduce

Configure Yarn 2.1.1:

yarn set version berry
yarn set version 2.1.1

$ yarn --version
2.1.1
$ node --version
v14.8.0
$ ~/.nvm/versions/node/v14.8.0/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v14.8.0
$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v14.8.0

Expected output of the last command is v12.16.1

Works as expected with Yarn 1:

$ yarn --version
1.22.4
$ node --version
v14.8.0
$ ~/.nvm/versions/node/v14.8.0/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
yarn node v1.22.4
v14.8.0
Done in 0.05s.
$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
yarn node v1.22.4
v12.16.1
Done in 0.04s.

Environment if relevant (please complete the following information):

• OS: Linux
• Node version 12.16.1, 14.8.0
• Yarn version 1.22.4, 2.1.1

Additional context

There is an unpleasant consequence: when node is not in PATH, yarn node ... cannot be run:

$ nvm deactivate
/home/segrey/.nvm/*/bin removed from ${PATH}
$ node --version

Command 'node' not found, but can be installed with:

sudo apt install nodejs

$ ~/.nvm/versions/node/v14.8.0/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
/usr/bin/env: ‘node’: No such file or directory

This caused https://youtrack.jetbrains.com/issue/WEB-46371.

[segrey]

Looks like a regression (#502). @arcanis

[merceyz]

Thought we fixed this in #1403 🤔

[segrey]

@merceyz Ooops, I'm sorry, actually the issue targeted Yarn version 2.1.1-git.20200806.1b11fbd5 (version from https://github.com/facebook/jest as of now), not Yarn 2.1.1.
It works correctly with Yarn 2.1.1, closing. Nope it works correctly with yarn set version berry which reports 2.1.1 as yarn --version. But it fails if yarn updated with yarn set version 2.1.1.

[merceyz]

2.1.1-git.20200806.1b11fbd5 is newer than 2.1.1 so if it doesn't work with that it's a regression

[segrey]

Interestingly, it works correctly after yarn set version berry, but fails after yarn set version 2.1.1. Both yarn installations report version 2.1.1 (is it ok?).
@merceyz Which one is newer?

$ yarn --version
1.22.4
$ node --version
v14.8.0
$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
yarn node v1.22.4
warning package.json: No license field
v12.16.1
Done in 0.12s.
$ yarn set version berry
warning package.json: No license field
Resolving berry to a url...
Downloading https://github.com/yarnpkg/berry/raw/master/packages/berry-cli/bin/berry.js...
Saving it into /home/segrey/samples/pnp/eslint-pnp-example/.yarn/releases/yarn-berry.js...
Updating /home/segrey/samples/pnp/eslint-pnp-example/.yarnrc.yml...
Done!
$ yarn --version
2.1.1
$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v12.16.1
$ yarn set version 2.1.1
➤ YN0000: Downloading https://github.com/yarnpkg/berry/raw/%40yarnpkg/cli/2.1.1/packages/yarnpkg-cli/bin/yarn.js
➤ YN0000: Saving the new release in .yarn/releases/yarn-2.1.1.cjs
➤ YN0000: Done in 0.89s
$ yarn --version
2.1.1
$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v14.8.0

[merceyz]

They should both be the same

[segrey]

@merceyz You're right, they are the same. Looks like this issue is caused by .cjs extension, everything works fine with .js extension:

$ yarn set version berry
warning package.json: No license field
Resolving berry to a url...
Downloading https://github.com/yarnpkg/berry/raw/master/packages/berry-cli/bin/berry.js...
Saving it into /home/segrey/samples/pnp/eslint-pnp-example/.yarn/releases/yarn-berry.js...
Updating /home/segrey/samples/pnp/eslint-pnp-example/.yarnrc.yml...
Done!

$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v12.16.1

$ mv .yarn/releases/yarn-berry.js .yarn/releases/yarn-berry.cjs 

$ sed -i 's/yarn-berry.js/yarn-berry.cjs/g' .yarnrc.yml 

$ ~/.nvm/versions/node/v12.16.1/bin/node /usr/share/yarn/bin/yarn.js node -e "console.log(process.version)"
v14.8.0

[merceyz]

Ah, that's a issue in how V1 spawns Yarn. It was fixed in yarnpkg/yarn#8144 but the CI is broken for V1 so it hasn't been released yet

[merceyz]

The fix has been released in V1, update your global Yarn version and the .cjs extension shouldn't be a problem anymore

[segrey]

@merceyz It works now correctly. Thank you!