title: Gatsby cannot find fs despite npm install
body: <p>I'm on:</p>
  
  <ul>
  <li>Ubuntu 16.04</li>
  <li>Gatsby CLI version: 2.7.14</li>
  <li>Gatsby version: 2.13.21</li>
  <li>Node v10.16.0</li>
  <li>NPM 6.10.1</li>
  </ul>
  
  <p>I'm following the Gatsby tutorial <a href="https://www.gatsbyjs.org/tutorial/part-seven/" rel="noreferrer">"7. Programmatically create pages from data"</a>. I can't solve this error:</p>
  
  <pre><code>This dependency was not found:
  ⠀
  * fs in ./node_modules/electron/index.js,
  ⠀
  To install it, you can run: npm install --save fs
  </code></pre>
  
  <p>I've run <code>npm install --save fs</code> already, and then tried it again. But the same error occurs. Permissions for the directory are set as <code>a+rwx</code> and everything has been installing fine up till this point.</p>
  
  <p>This error happens when I add this code to gatsby-node.js as the tutorial says to:</p>
  
  <pre><code>const { createFilePath } = require(`gatsby-source-filesystem`)
  
  exports.onCreateNode = ({ node, getNode }) =&gt; {
    if (node.internal.type === `MarkdownRemark`) {
      console.log(createFilePath({ node, getNode, basePath: `pages` }))
    }
  }
  </code></pre>
  
  <p>The full flow of events when I run <code>gatsby develop -p 8001</code>:</p>
  
  <pre><code>success open and validate gatsby-configs - 0.070 s
  success load plugins - 0.636 s
  success onPreInit - 0.005 s
  success initialize cache - 0.012 s
  success copy gatsby files - 0.092 s
  success onPreBootstrap - 0.026 s
  success source and transform nodes - 0.145 s
  success building schema - 0.560 s
  success createPages - 0.003 s
  success createPagesStatefully - 0.078 s
  success onPreExtractQueries - 0.004 s
  success update schema - 0.087 s
  success extract queries from components - 0.340 s
  success write out requires - 0.009 s
  success write out redirect data - 0.006 s
  success onPostBootstrap - 0.003 s
  ⠀
  info bootstrap finished - 9.246 s
  ⠀
  success run static queries - 0.051 s — 1/1 23.83 queries/second
  success run page queries - 0.040 s — 3/3 135.00 queries/second
   ERROR  Failed to compile with 7 errors                     10:01:07 PM
  ⠀
  This dependency was not found:
  ⠀
  * fs in ./node_modules/electron/index.js,
  ⠀
  To install it, you can run: npm install --save fs
  ✖ ｢wdm｣:
  ERROR in ./node_modules/electron/index.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/electron'
   @ ./node_modules/electron/index.js 1:9-22
   @ ./node_modules/gatsby-source-filesystem/node_modules/got/index.js
   @ ./node_modules/gatsby-source-filesystem/create-remote-file-node.js
   @ ./node_modules/gatsby-source-filesystem/index.js
   @ ./src/pages/gatsby-node.js
   @ ./.cache/sync-requires.js
   @ ./.cache/app.js
   @ multi ./node_modules/event-source-polyfill/src/eventsource.js
  (webpack)-hot-middleware/client.js?path=/__webpack_hmr&amp;reload=true&amp;over
  lay=false ./.cache/app
  
  ERROR in ./node_modules/fs-extra/lib/empty/index.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/fs-extra/lib/empty'
   @ ./node_modules/fs-extra/lib/empty/index.js 4:11-24
   @ ./node_modules/fs-extra/lib/index.js
   @ ./node_modules/gatsby-source-filesystem/index.js
   @ ./src/pages/gatsby-node.js
   @ ./.cache/sync-requires.js
   @ ./.cache/app.js
   @ multi ./node_modules/event-source-polyfill/src/eventsource.js
  (webpack)-hot-middleware/client.js?path=/__webpack_hmr&amp;reload=true&amp;over
  lay=false ./.cache/app
  
  ERROR in ./node_modules/graceful-fs/graceful-fs.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/graceful-fs'
   @ ./node_modules/graceful-fs/graceful-fs.js 1:9-22
   @ ./node_modules/fs-extra/lib/fs/index.js
   @ ./node_modules/fs-extra/lib/index.js
   @ ./node_modules/gatsby-source-filesystem/index.js
   @ ./src/pages/gatsby-node.js
   @ ./.cache/sync-requires.js
   @ ./.cache/app.js
   @ multi ./node_modules/event-source-polyfill/src/eventsource.js
  (webpack)-hot-middleware/client.js?path=/__webpack_hmr&amp;reload=true&amp;over
  lay=false ./.cache/app
  
  ERROR in ./node_modules/jsonfile/index.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/jsonfile'
   @ ./node_modules/jsonfile/index.js 5:8-21
   @ ./node_modules/fs-extra/lib/json/jsonfile.js
   @ ./node_modules/fs-extra/lib/json/index.js
   @ ./node_modules/fs-extra/lib/index.js
   @ ./node_modules/gatsby-source-filesystem/index.js
   @ ./src/pages/gatsby-node.js
   @ ./.cache/sync-requires.js
   @ ./.cache/app.js
   @ multi ./node_modules/event-source-polyfill/src/eventsource.js
  (webpack)-hot-middleware/client.js?path=/__webpack_hmr&amp;reload=true&amp;over
  lay=false ./.cache/app
  
  ERROR in ./node_modules/md5-file/index.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/md5-file'
   @ ./node_modules/md5-file/index.js 4:9-22
   @ ./node_modules/gatsby-source-filesystem/create-file-node.js
   @
  ./node_modules/gatsby-source-filesystem/create-file-node-from-buffer.js
   @ ./node_modules/gatsby-source-filesystem/index.js
   @ ./src/pages/gatsby-node.js
   @ ./.cache/sync-requires.js
   @ ./.cache/app.js
   @ multi ./node_modules/event-source-polyfill/src/eventsource.js
  (webpack)-hot-middleware/client.js?path=/__webpack_hmr&amp;reload=true&amp;over
  lay=false ./.cache/app
  
  ERROR in ./node_modules/read-chunk/index.js
  Module not found: Error: Can't resolve 'fs' in
  '/home/testjs/tutorial-part-four/node_modules/read-chunk'
   @ ./node_modules/read-chunk/index.js 2:11-24
  ℹ ｢wdm｣: Failed to compile.
  </code></pre>
  
  <p>I googled this error and it pops up in several contexts, none of which match this case with Gatsby. I'm new to React and Gatsby (hence the tutorial), so I don't know how to deal with this yet. How should I fix it?</p>