anchor.diff:  $ yarn install
   </pre>
   
  -When you push the app, the buildpack looks for an `npm-packages-offline-cache` directory at the top level of the app directory. If this directory exists, the buildpack runs Yarn in offline mode. Otherwise, it runs Yarn normally, which requires an Internet connection.
  +When you push the app, the buildpack looks for an `npm-packages-offline-cache` directory at the top level of the app directory.
  +If this directory exists, the buildpack runs Yarn in offline mode. Otherwise, it runs Yarn normally, which may require an Internet connection.
  +It is not strictly necessary to provide a `node_modules` directory when running Yarn in offline mode, as the offline cache will provide the dependencies.
   
   For more information about using an offline mirror with Yarn, see the [Yarn Blog](https://yarnpkg.com/blog/2016/11/24/offline-mirror).
   
  
positive.code: Staging failed: Buildpack compilation step failed
  </pre>
  
  ## <a id='vendoring'></a>Vendor App Dependencies ##
  
  To vendor dependencies for an app using the Node.js buildpack, run `npm install` from your app directory. This command vendors dependencies into the `node_modules` directory of your app directory.
  
  For example, the following example vendors dependencies into the `my-nodejs-app/node_modules` directory:
  
  
negative.code: 
  The `cf push` command uploads the vendored dependencies with the app.
  
  <p class='note'><strong>Note</strong>: For an app to run in a disconnected environment, it must vendor its dependencies and provide a lock file.</p>
  
  ### <a id='offline_environments'></a>Usage in Offline Environments ###
  
  When vendoring apps for usage in offline environments, it is important to also supply a [lock file](https://docs.npmjs.com/files/package-locks).
  NPM's lock file is called [`package-lock.json`](https://docs.npmjs.com/files/package-lock.json), and Yarn's lock file is called [`yarn.lock`](https://yarnpkg.com/lang/en/docs/yarn-lock/).
  This lock file will inform the package manager of the exact versions of dependencies and transitive dependencies to look for when running `npm install` or `yarn install`.
  Because of this, it is important to keep `package.json`, the vendored `node_modules` directory, and your lock file all in sync to avoid network calls.
  
  <p class='note'><strong>Note</strong>: <code>package-lock.json</code> is only supported by NPM 5.x and later. For earlier versions of NPM, provide a <a href='https://docs.npmjs.com/files/shrinkwrap.json'><code>npm-shrinkwrap.json</code></a> file instead.</p>
  
  #### <a id='yarn_offline'></a>Yarn Offline Mode ####
  
  Versions 1.5.28 and later of the Node.js buildpack include the ability to use Yarn in offline mode.
  To do so, you must mirror the Yarn registry locally by providing an `npm-packages-offline-cache` directory:
  
  <pre class="terminal">
  $ cd APP-DIR
  