diff --git a/packages/@vue/cli-service/lib/PluginAPI.js b/packages/@vue/cli-service/lib/PluginAPI.js
index 34232a054..25457b626 100644
--- a/packages/@vue/cli-service/lib/PluginAPI.js
+++ b/packages/@vue/cli-service/lib/PluginAPI.js
@@ -17,6 +17,13 @@ class PluginAPI {
     this.service = service
   }
 
+  /**
+   * Current working directory.
+   */
+  getCwd () {
+    return this.service.context
+  }
+
   /**
    * Resolve path for a project.
    *
diff --git a/packages/@vue/cli-service/lib/commands/serve.js b/packages/@vue/cli-service/lib/commands/serve.js
index c339d9791..759da33a7 100644
--- a/packages/@vue/cli-service/lib/commands/serve.js
+++ b/packages/@vue/cli-service/lib/commands/serve.js
@@ -1,6 +1,6 @@
 const {
   info,
-  hasYarn,
+  hasProjectYarn,
   openBrowser,
   IpcMessenger
 } = require('@vue/cli-shared-utils')
@@ -193,7 +193,7 @@ module.exports = (api, options) => {
           isFirstCompile = false
 
           if (!isProduction) {
-            const buildCommand = hasYarn() ? `yarn build` : `npm run build`
+            const buildCommand = hasProjectYarn(api.getCwd()) ? `yarn build` : `npm run build`
             console.log(`  Note that the development build is not optimized.`)
             console.log(`  To create a production build, run ${chalk.cyan(buildCommand)}.`)
           } else {
diff --git a/packages/@vue/cli-shared-utils/lib/env.js b/packages/@vue/cli-shared-utils/lib/env.js
index 96c2aed11..7c14bde29 100644
--- a/packages/@vue/cli-shared-utils/lib/env.js
+++ b/packages/@vue/cli-shared-utils/lib/env.js
@@ -1,7 +1,11 @@
 const { execSync } = require('child_process')
+const fs = require('fs')
+const path = require('path')
 
 let _hasYarn
+const _yarnProjects = new Map()
 let _hasGit
+const _gitProjects = new Map()
 
 // env detection
 exports.hasYarn = () => {
@@ -19,6 +23,22 @@ exports.hasYarn = () => {
   }
 }
 
+exports.hasProjectYarn = (cwd) => {
+  if (_yarnProjects.has(cwd)) {
+    return checkYarn(_yarnProjects.get(cwd))
+  }
+
+  const lockFile = path.join(cwd, 'yarn.lock')
+  const result = fs.existsSync(lockFile)
+  _yarnProjects.set(cwd, result)
+  return checkYarn(result)
+}
+
+function checkYarn (result) {
+  if (result && !exports.hasYarn()) throw new Error(`The project seems to require yarn but it's not installed.`)
+  return result
+}
+
 exports.hasGit = () => {
   if (process.env.VUE_CLI_TEST) {
     return true
@@ -33,3 +53,20 @@ exports.hasGit = () => {
     return (_hasGit = false)
   }
 }
+
+exports.hasProjectGit = (cwd) => {
+  if (_gitProjects.has(cwd)) {
+    return _gitProjects.get(cwd)
+  }
+
+  let result
+  try {
+    execSync('git status', { stdio: 'ignore', cwd })
+    result = true
+  } catch (e) {
+    result = false
+  }
+  console.log('hasProjectGit', cwd, result)
+  _gitProjects.set(cwd, result)
+  return result
+}
diff --git a/packages/@vue/cli-ui/apollo-server/connectors/dependencies.js b/packages/@vue/cli-ui/apollo-server/connectors/dependencies.js
index e7c1494da..249ace300 100644
--- a/packages/@vue/cli-ui/apollo-server/connectors/dependencies.js
+++ b/packages/@vue/cli-ui/apollo-server/connectors/dependencies.js
@@ -150,7 +150,7 @@ function install ({ id, type }, context) {
       status: 'dependency-install',
       args: [id]
     })
-    await installPackage(cwd.get(), getCommand(), null, id, type === 'devDependencies')
+    await installPackage(cwd.get(), getCommand(cwd.get()), null, id, type === 'devDependencies')
 
     logs.add({
       message: `Dependency ${id} installed`,
@@ -178,7 +178,7 @@ function uninstall ({ id }, context) {
 
     const dep = findOne(id, context)
 
-    await uninstallPackage(cwd.get(), getCommand(), null, id)
+    await uninstallPackage(cwd.get(), getCommand(cwd.get()), null, id)
 
     logs.add({
       message: `Dependency ${id} uninstalled`,
@@ -204,7 +204,7 @@ function update ({ id }, context) {
 
     const dep = findOne(id, context)
     const { current, wanted } = await getVersion(dep, context)
-    await updatePackage(cwd.get(), getCommand(), null, id)
+    await updatePackage(cwd.get(), getCommand(cwd.get()), null, id)
 
     logs.add({
       message: `Dependency ${id} updated from ${current} to ${wanted}`,
@@ -249,7 +249,7 @@ function updateAll (context) {
       args: [updatedDeps.length]
     })
 
-    await updatePackage(cwd.get(), getCommand(), null, updatedDeps.map(
+    await updatePackage(cwd.get(), getCommand(cwd.get()), null, updatedDeps.map(
       p => p.id
     ).join(' '))
 
diff --git a/packages/@vue/cli-ui/apollo-server/connectors/git.js b/packages/@vue/cli-ui/apollo-server/connectors/git.js
index 3d72e7bc8..07011150e 100644
--- a/packages/@vue/cli-ui/apollo-server/connectors/git.js
+++ b/packages/@vue/cli-ui/apollo-server/connectors/git.js
@@ -3,8 +3,12 @@ const path = require('path')
 const parseDiff = require('../util/parse-diff')
 // Connectors
 const cwd = require('./cwd')
+// Utils
+const { hasProjectGit } = require('@vue/cli-shared-utils')
 
 async function getNewFiles (context) {
+  if (!hasProjectGit(cwd.get())) return []
+
   const { stdout } = await execa('git', [
     'ls-files',
     '-o',
@@ -20,6 +24,8 @@ async function getNewFiles (context) {
 }
 
 async function getDiffs (context) {
+  if (!hasProjectGit(cwd.get())) return []
+
   const newFiles = await getNewFiles(context)
   await execa('git', ['add', '-N', '*'], {
     cwd: cwd.get()
@@ -40,6 +46,8 @@ async function getDiffs (context) {
 }
 
 async function commit (message, context) {
+  if (!hasProjectGit(cwd.get())) return false
+
   await execa('git', ['add', '*'], {
     cwd: cwd.get()
   })
@@ -50,6 +58,8 @@ async function commit (message, context) {
 }
 
 async function reset (context) {
+  if (!hasProjectGit(cwd.get())) return false
+
   await execa('git', ['reset'], {
     cwd: cwd.get()
   })
@@ -57,6 +67,8 @@ async function reset (context) {
 }
 
 async function getRoot (context) {
+  if (!hasProjectGit(cwd.get())) return cwd.get()
+
   const { stdout } = await execa('git', [
     'rev-parse',
     '--show-toplevel'
diff --git a/packages/@vue/cli-ui/apollo-server/connectors/plugins.js b/packages/@vue/cli-ui/apollo-server/connectors/plugins.js
index f88562928..ec34687b0 100644
--- a/packages/@vue/cli-ui/apollo-server/connectors/plugins.js
+++ b/packages/@vue/cli-ui/apollo-server/connectors/plugins.js
@@ -217,7 +217,7 @@ function install (id, context) {
     if (process.env.VUE_CLI_DEBUG && isOfficialPlugin(id)) {
       mockInstall(id, context)
     } else {
-      await installPackage(cwd.get(), getCommand(), null, id)
+      await installPackage(cwd.get(), getCommand(cwd.get()), null, id)
     }
     await initPrompts(id, context)
     installationStep = 'config'
@@ -250,7 +250,7 @@ function uninstall (id, context) {
     if (process.env.VUE_CLI_DEBUG && isOfficialPlugin(id)) {
       mockUninstall(id, context)
     } else {
-      await uninstallPackage(cwd.get(), getCommand(), null, id)
+      await uninstallPackage(cwd.get(), getCommand(cwd.get()), null, id)
     }
     currentPluginId = null
     installationStep = null
@@ -330,7 +330,7 @@ function update (id, context) {
     const plugin = findOne(id, context)
     const { current, wanted } = await dependencies.getVersion(plugin, context)
 
-    await updatePackage(cwd.get(), getCommand(), null, id)
+    await updatePackage(cwd.get(), getCommand(cwd.get()), null, id)
 
     logs.add({
       message: `Plugin ${id} updated from ${current} to ${wanted}`,
@@ -377,7 +377,7 @@ async function updateAll (context) {
       args: [updatedPlugins.length]
     })
 
-    await updatePackage(cwd.get(), getCommand(), null, updatedPlugins.map(
+    await updatePackage(cwd.get(), getCommand(cwd.get()), null, updatedPlugins.map(
       p => p.id
     ).join(' '))
 
diff --git a/packages/@vue/cli-ui/apollo-server/util/command.js b/packages/@vue/cli-ui/apollo-server/util/command.js
index aa94cbe3c..64e37dcef 100644
--- a/packages/@vue/cli-ui/apollo-server/util/command.js
+++ b/packages/@vue/cli-ui/apollo-server/util/command.js
@@ -1,8 +1,12 @@
 const {
-  hasYarn
+  hasYarn,
+  hasProjectYarn
 } = require('@vue/cli-shared-utils')
 const { loadOptions } = require('@vue/cli/lib/options')
 
-exports.getCommand = function () {
-  return loadOptions().packageManager || (hasYarn() ? 'yarn' : 'npm')
+exports.getCommand = function (cwd = undefined) {
+  if (!cwd) {
+    return loadOptions().packageManager || (hasYarn() ? 'yarn' : 'npm')
+  }
+  return hasProjectYarn(cwd) ? 'yarn' : 'npm'
 }
diff --git a/packages/@vue/cli-ui/locales/en.json b/packages/@vue/cli-ui/locales/en.json
index 6323eb840..506c3196f 100644
--- a/packages/@vue/cli-ui/locales/en.json
+++ b/packages/@vue/cli-ui/locales/en.json
@@ -16,6 +16,7 @@
           "files-changed": "Files changed",
           "search-file": "Search file",
           "empty": "No change found",
+          "error": "Couldn't get file changes",
           "modals": {
             "commit": {
               "title": "Commit changes",
diff --git a/packages/@vue/cli/lib/Creator.js b/packages/@vue/cli/lib/Creator.js
index cfa32e02f..1f7ed99fc 100644
--- a/packages/@vue/cli/lib/Creator.js
+++ b/packages/@vue/cli/lib/Creator.js
@@ -30,6 +30,7 @@ const {
   warn,
   error,
   hasGit,
+  hasProjectGit,
   hasYarn,
   logWithSpinner,
   stopSpinner,
@@ -443,17 +444,9 @@ module.exports = class Creator extends EventEmitter {
       return false
     }
     if (cliOptions.git) {
-      return cliOptions.git !== 'false'
+      return cliOptions.git !== 'false' && cliOptions.git !== false
     }
-    // check if we are in a git repo already
-    try {
-      await this.run('git', ['status'])
-    } catch (e) {
-      // if git status failed, let's create a fresh repo
-      return true
-    }
-    // if git status worked, it means we are already in a git repo
-    // so don't init again.
-    return false
+
+    return !hasProjectGit(this.context)
   }
 }
diff --git a/packages/@vue/cli/lib/add.js b/packages/@vue/cli/lib/add.js
index 6ed310633..08f54b23a 100644
--- a/packages/@vue/cli/lib/add.js
+++ b/packages/@vue/cli/lib/add.js
@@ -6,7 +6,7 @@ const { resolveModule, loadModule } = require('./util/module')
 const {
   log,
   error,
-  hasYarn,
+  hasProjectYarn,
   stopSpinner,
   resolvePluginId
 } = require('@vue/cli-shared-utils')
@@ -26,7 +26,7 @@ async function add (pluginName, options = {}, context = process.cwd()) {
   log(`📦  Installing ${chalk.cyan(packageName)}...`)
   log()
 
-  const packageManager = loadOptions().packageManager || (hasYarn() ? 'yarn' : 'npm')
+  const packageManager = loadOptions().packageManager || (hasProjectYarn(context) ? 'yarn' : 'npm')
   await installPackage(context, packageManager, null, packageName)
 
   stopSpinner()
diff --git a/packages/@vue/cli/lib/invoke.js b/packages/@vue/cli/lib/invoke.js
index 1f93db647..bda2fdf91 100644
--- a/packages/@vue/cli/lib/invoke.js
+++ b/packages/@vue/cli/lib/invoke.js
@@ -13,8 +13,8 @@ const normalizeFilePaths = require('./util/normalizeFilePaths')
 const {
   log,
   error,
-  hasYarn,
-  hasGit,
+  hasProjectYarn,
+  hasProjectGit,
   logWithSpinner,
   stopSpinner,
   resolvePluginId
@@ -122,7 +122,7 @@ async function runGenerator (context, plugin, pkg = getPkg(context)) {
   if (!isTestOrDebug && depsChanged) {
     log(`📦  Installing additional dependencies...`)
     const packageManager =
-      loadOptions().packageManager || (hasYarn() ? 'yarn' : 'npm')
+      loadOptions().packageManager || (hasProjectYarn(context) ? 'yarn' : 'npm')
     await installDeps(context, packageManager)
   }
 
@@ -137,7 +137,7 @@ async function runGenerator (context, plugin, pkg = getPkg(context)) {
 
   log()
   log(`   Successfully invoked generator for plugin: ${chalk.cyan(plugin.id)}`)
-  if (!process.env.VUE_CLI_TEST && hasGit()) {
+  if (!process.env.VUE_CLI_TEST && hasProjectGit(context)) {
     const { stdout } = await execa('git', [
       'ls-files',
       '--exclude-standard',
@@ -157,14 +157,14 @@ async function runGenerator (context, plugin, pkg = getPkg(context)) {
         )
       )
       log()
+      log(
+        `   You should review these changes with ${chalk.cyan(
+          `git diff`
+        )} and commit them.`
+      )
+      log()
     }
   }
-  log(
-    `   You should review these changes with ${chalk.cyan(
-      `git diff`
-    )} and commit them.`
-  )
-  log()
 
   generator.printExitLogs()
 }