fix: clone options before mutating

packages/@vue/cli/lib/Creator.js

@@ -5,6 +5,7 @@ const execa = require('execa')
 const resolve = require('resolve')
 const inquirer = require('inquirer')
 const Generator = require('./Generator')
+const cloneDeep = require('lodash.clonedeep')
 const sortObject = require('./util/sortObject')
 const installDeps = require('./util/installDeps')
 const clearConsole = require('./util/clearConsole')
@@ -71,6 +72,8 @@ module.exports = class Creator {
       options = await this.promptAndResolveOptions()
     }
 
+    // clone before mutating
+    options = cloneDeep(options)
     // inject core service
     options.plugins['@vue/cli-service'] = Object.assign({
       projectName: name

packages/@vue/cli/package.json

@@ -37,6 +37,7 @@
     "inquirer": "^4.0.1",
     "isbinaryfile": "^3.0.2",
     "klaw-sync": "^3.0.2",
+    "lodash.clonedeep": "^4.5.0",
     "minimist": "^1.2.0",
     "mkdirp": "^0.5.1",
     "resolve": "^1.5.0",

yarn.lock

@@ -6355,6 +6355,10 @@ lodash.clone@3.0.3:
     lodash._bindcallback "^3.0.0"
     lodash._isiterateecall "^3.0.0"
 
+lodash.clonedeep@^4.5.0:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz#e23f3f9c4f8fbdde872529c1071857a086e5ccef"
+
 lodash.cond@^4.3.0:
   version "4.5.2"
   resolved "https://registry.yarnpkg.com/lodash.cond/-/lodash.cond-4.5.2.tgz#f471a1da486be60f6ab955d17115523dd1d255d5"