fix: use yarn --version to detect yarn (#4336)

haoqunjiang · haoqunjiang · commit 470c94ee1a17 · 2019-08-02T18:41:34.000+08:00
- We never referred to `yarnpkg` anywhere else in the codebase - For the rare case that `yarn` binary is overridden by Hadoop YARN, `yarn --version` will throw (it only supports `yarn version`), therefore it won't pass this check. Fixes #3941. Closes #3942. (cherry picked from commit 448dbdb)
diff --git a/packages/@vue/cli-shared-utils/lib/env.js b/packages/@vue/cli-shared-utils/lib/env.js
@@ -24,7 +24,7 @@ exports.hasYarn = () => {
     return _hasYarn
   }
   try {
-    execSync('yarnpkg --version', { stdio: 'ignore' })
+    execSync('yarn --version', { stdio: 'ignore' })
     return (_hasYarn = true)
   } catch (e) {
     return (_hasYarn = false)

Original file line number	Diff line number	Diff line change
`@@ -24,7 +24,7 @@ exports.hasYarn = () => {`
`24`	`24`	`return _hasYarn`
`25`	`25`	`}`
`26`	`26`	`try {`
`27`		`- execSync('yarnpkg --version', { stdio: 'ignore' })`
	`27`	`+ execSync('yarn --version', { stdio: 'ignore' })`
`28`	`28`	`return (_hasYarn = true)`
`29`	`29`	`} catch (e) {`
`30`	`30`	`return (_hasYarn = false)`