title: /bin/sh: SET: command not found
body: <p>I cloned a react project that contains the following <code>package.json</code>. After <code>yarn</code>, <code>yarn start</code> gave me the following error. I tried <code>yarn add react-scripts start</code>, but it still did not work. </p>
  
  <p>I am using MacOS.</p>
  
  <p>Could anyone help? </p>
  
  <pre><code>$ yarn start
  yarn run v1.21.1
  $ SET PORT=8000 &amp;&amp; react-scripts start
  /bin/sh: SET: command not found
  error Command failed with exit code 127.
  info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
  </code></pre>
  
  <p><code>package.json</code>:</p>
  
  <pre><code>{
    "name": "frontend",
    "version": "0.1.0",
    "private": true,
    "dependencies": {
      "@material-ui/core": "^4.9.8",
      "@microsoft/office-js-helpers": "^1.0.2",
      "@testing-library/jest-dom": "^4.2.4",
      "@testing-library/react": "^9.3.2",
      "@testing-library/user-event": "^7.1.2",
      "@types/react-stripe-elements": "^6.0.4",
      "@uifabric/react-cards": "^0.109.49",
      "axios": "^0.19.2",
      "color": "^3.1.2",
      "cross-storage": "^1.0.0",
      "dva": "^2.4.1",
      "dva-model-creator": "^0.4.3",
      "formik": "^2.1.4",
      "lodash": "^4.17.15",
      "moment": "^2.24.0",
      "monaco-editor": "^0.20.0",
      "node-sass": "^4.13.1",
      "office-ui-fabric-react": "^7.105.4",
      "query-string": "^6.11.1",
      "react": "^16.13.1",
      "react-app-polyfill": "^1.0.6",
      "react-dom": "^16.13.1",
      "react-monaco-editor": "^0.35.0",
      "react-scripts": "3.4.1",
      "react-stripe-elements": "^6.1.1",
      "redux-devtools-extension": "^2.13.8",
      "styled-components": "^5.0.1",    
      "typescript": "^3.8.3",
      "yup": "^0.28.3"
    },
    "scripts": {
      "start": "SET PORT=8000 &amp;&amp; react-scripts start",
      "build": "react-scripts --max_old_space_size=8096 build",
      "test": "react-scripts test",
      "eject": "react-scripts eject"
    },
    "eslintConfig": {
      "extends": "react-app"
    },
    "browserslist": {
      "production": [
        "&gt;0.2%",
        "not dead",
        "not op_mini all"
      ],
      "development": [
        "last 1 chrome version",
        "last 1 firefox version",
        "last 1 safari version"
      ]
    },
    "devDependencies": {
      "@types/color": "^3.0.1",
      "@types/cross-storage": "^0.8.29",
      "@types/jest": "^25.1.4",
      "@types/lodash": "^4.14.149",
      "@types/node": "^13.9.5",
      "@types/query-string": "^6.3.0",
      "@types/react": "^16.9.27",
      "@types/react-dom": "^16.9.5",
      "@types/react-redux": "^7.1.7",
      "@types/styled-components": "^5.0.1",
      "@types/yup": "^0.26.33"
    }
  }
  </code></pre>