title: NPM - Failed to replace env in config: ${NPM_TOKEN}
body: <p>I am trying to build a react app, but when I execute the command <code>npm -i</code> it gives me the following error:</p>
  
  <pre><code>Error: Failed to replace env in config: ${NPM_TOKEN}
      at /usr/local/lib/node_modules/npm/lib/config/core.js:415:13
      at String.replace (&lt;anonymous&gt;)
      at envReplace (/usr/local/lib/node_modules/npm/lib/config/core.js:411:12)
      at parseField (/usr/local/lib/node_modules/npm/lib/config/core.js:389:7)
      at /usr/local/lib/node_modules/npm/lib/config/core.js:330:24
      at Array.forEach (&lt;anonymous&gt;)
      at Conf.add (/usr/local/lib/node_modules/npm/lib/config/core.js:328:23)
      at ConfigChain.addString (/usr/local/lib/node_modules/npm/node_modules/config-chain/index.js:244:8)
      at Conf.&lt;anonymous&gt; (/usr/local/lib/node_modules/npm/lib/config/core.js:316:10)
      at /usr/local/lib/node_modules/npm/node_modules/graceful-fs/graceful-fs.js:78:16
  /usr/local/lib/node_modules/npm/lib/npm.js:61
        throw new Error('npm.load() required')
        ^
  
  Error: npm.load() required
      at Object.get (/usr/local/lib/node_modules/npm/lib/npm.js:61:13)
      at process.errorHandler (/usr/local/lib/node_modules/npm/lib/utils/error-handler.js:205:18)
      at process.emit (events.js:182:13)
      at process._fatalException (internal/bootstrap/node.js:448:27)
  </code></pre>
  
  <p>I am using MacOS High Sierra. I tried to set the NPM_TOKEN as an environment variable with following command:</p>
  
  <pre><code>set -x NPM_TOKEN = xyz
  </code></pre>
  
  <p>but it doesn't work.
  What is the problem?</p>