yarn 1.12.1 break support for node 4

[jbustamovej]

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

What is the current behavior?
yarn return "SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode"

If the current behavior is a bug, please provide the steps to reproduce.
➜ ~ node --version
v4.9.1
➜ ~ npm i -g yarn
/Users/joshua/.nvm/versions/node/v4.9.1/bin/yarn -> /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/bin/yarn.js
/Users/joshua/.nvm/versions/node/v4.9.1/bin/yarnpkg -> /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/bin/yarn.js
yarn@1.12.1 /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn
➜ ~ yarn --version
/Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/lib/cli.js:62909
let code = codeRegex();
^^^

SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
at exports.runInThisContext (vm.js:53:16)
at Module._compile (module.js:373:25)
at Object.Module._extensions..js (module.js:416:10)
at Module.load (module.js:343:32)
at Function.Module._load (module.js:300:12)
at Module.require (module.js:353:17)
at require (internal/module.js:12:17)
at Object. (/Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/bin/yarn.js:24:13)
at Module._compile (module.js:409:26)
at Object.Module._extensions..js (module.js:416:10)
➜ ~ npm i -g yarn@1.11.1
/Users/joshua/.nvm/versions/node/v4.9.1/bin/yarn -> /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/bin/yarn.js
/Users/joshua/.nvm/versions/node/v4.9.1/bin/yarnpkg -> /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn/bin/yarn.js
yarn@1.11.1 /Users/joshua/.nvm/versions/node/v4.9.1/lib/node_modules/yarn
➜ ~ yarn --version
1.11.1

What is the expected behavior?
No syntax error

Please mention your node.js, yarn and operating system version.
node 4.9.1, mac osx 10.14.1, same problem on ubuntu and centos

[arcanis]

This likely comes from a dependency we use, because the build pipeline hasn't changed. Maybe something added / upgraded to yarn audit.

I would definitely merge a PR that would fix this. In the meantime, you can use the yarn-legacy build (cf on the release page): I checked it and it seems to work fine.

[arcanis]

Also note that Yarn 2 will drop support for Node 4 - I'd suggest to upgrade to Node 8+ if possible (it's not clear whether we'll want to support Node 6, cf this rfc).

[rally25rs]

This should have been fixed in 1.12.1 by #6535 😕

[VincentLanglet]

Actually this is not fixed. Both node 4 and node 5 are not supported.

nvm install 4
yarn --version

or

nvm install 5
yarn --version

return the following error

/usr/local/yarn-latest/lib/cli.js:45699
  let {
      ^
SyntaxError: Unexpected token {
    at NativeCompileCache._moduleCompile (/usr/local/yarn-latest/lib/v8-compile-cache.js:226:18)
    at Module._compile (/usr/local/yarn-latest/lib/v8-compile-cache.js:172:36)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Module.require (module.js:367:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/usr/local/yarn-latest/bin/yarn.js:24:13)
    at Module._compile (module.js:413:34)
    at Object.Module._extensions..js (module.js:422:10)

[rally25rs]

It looks like this is caused by yarn's dependency on @zkochan/cmd-shim when it was upgraded in #6804 What's weird is that in the PR, the node v4 tests pass 😕

But the upgrade to v3.1.0 added an object destructuring:

https://github.com/pnpm/cmd-shim/blob/%40zkochan/cmd-shim/3.1.0/index.js#L89-L92

and since dependencies aren't babel transpiled by default, that is getting included in the built deployment of yarn.

@arcanis any thoughts on this? It seems weird that the node v4 tests passed for that PR... unless the code is transpiled differently for the tests vs the deployment build...

[paul-soporan]

Closing as we're now focusing on Yarn 2+ which dropped support for all Node versions below Node 10.