无法在devDependencies中找到“@ angular / cli”

Question

我在安装Angular时发现了以下问题。

$ node -v
v9.10.1
$ npm -v
5.8.0
$ ng --version

Unable to find "@angular/cli" in devDependencies.

Please take the following steps to avoid issues:
"npm install --save-dev @angular/cli@latest"


    _                      _                 ____ _     ___
   / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
  / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
 / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
/_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
               |___/

Angular CLI: 1.7.4
Node: 9.10.1
OS: darwin x64
Angular: undefined
...


typescript: error
webpack: error

正如您所看到的，Angular版本是“未定义”，cli和typescript，webpack是一个错误。这是我的问题。我试图创建一个项目。

$ ng new test-proj
You cannot use the new command inside an Angular CLI project.

我跟着Angular guide page，但我没有成功。

// package.json
{
  "name": "test",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "repository": {
    "type": "git",
    "url": "git+ ... skip ... "
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": " ... skip ... "
  },
  "homepage": " ... skip ... ",
  "dependencies": {
    "formidable": "^1.2.1"
  },
  "devDependencies": {
    "@angular/cli": "^1.7.4"
  },
  "keywords": [],
  "description": ""
}

请帮帮我。 怎么了？