title: "Backend not found" with netlifyCMS and Gatsby
body: <p>I've been trying to setup NetlifyCMS on a really basic Gatsby app made via cloning the <a href="https://github.com/gatsbyjs/gatsby-starter-default" rel="nofollow noreferrer">gatsby-starter-default</a>. I followed the <a href="https://www.gatsbyjs.org/docs/sourcing-from-netlify-cms/" rel="nofollow noreferrer">Sourcing from Netlify CMS instructions</a> but I keep getting Backend not found error. Here's my Gatsby setup:</p>
  
  <p>/static/admin/config.yml</p>
  
  <pre><code>backend:
    name: appendtoStatic
    branch: master
  
  media_folder: static/img
  public_folder: /images
  
  collections:
    - name: "pages"
      label: "Pages"
      files:    
        - file: "src/pages/about.md"
          label: "About"
          name: "about"
          fields:
            - {
                label: "Template Key",
                name: "templateKey",
                widget: "hidden",
                default: "about-page",
              }
            - { label: "Title", name: "title", widget: "string" }
            - { label: "Body", name: "body", widget: "markdown" }
  </code></pre>
  
  <p>Here's my package.json</p>
  
  <pre><code>{
    "name": "gatsby-starter-default",
    "private": true,
    "description": "A simple starter to get up and developing quickly with Gatsby",
    "version": "0.1.0",
    "author": "Kyle Mathews &lt;mathews.kyle@gmail.com&gt;",
    "dependencies": {
      "gatsby": "^2.2.3",
      "gatsby-image": "^2.0.34",
      "gatsby-plugin-manifest": "^2.0.24",
      "gatsby-plugin-netlify-cms": "^3.0.17",
      "gatsby-plugin-offline": "^2.0.25",
      "gatsby-plugin-react-helmet": "^3.0.10",
      "gatsby-plugin-sharp": "^2.0.30",
      "gatsby-source-filesystem": "^2.0.27",
      "gatsby-transformer-remark": "^2.3.8",
      "gatsby-transformer-sharp": "^2.1.17",
      "netlify-cms": "^2.9.0",
      "prop-types": "^15.7.2",
      "react": "^16.8.4",
      "react-dom": "^16.8.4",
      "react-helmet": "^5.2.0"
    },
    "devDependencies": {
      "prettier": "^1.16.4"
    },
    "keywords": [
      "gatsby"
    ],
    "license": "MIT",
    "scripts": {
      "build": "gatsby build",
      "develop": "gatsby develop",
      "format": "prettier --write src/**/*.{js,jsx}",
      "start": "npm run develop",
      "serve": "gatsby serve",
      "test": "echo \"Write tests! -&gt; https://gatsby.dev/unit-testing\""
    },
    "repository": {
      "type": "git",
      "url": "https://github.com/gatsbyjs/gatsby-starter-default"
    },
    "bugs": {
      "url": "https://github.com/gatsbyjs/gatsby/issues"
    }
  }
  </code></pre>
  
  <p>My gatsby-config.js</p>
  
  <pre><code>module.exports = {
    siteMetadata: {
      title: `Gatsby Default Starter`,
      description: `Kick off your next, great Gatsby project with this default starter. This barebones starter ships with the main Gatsby configuration files you might need.`,
      author: `@gatsbyjs`,
    },
    plugins: [
      `gatsby-plugin-react-helmet`,
      {
        resolve: `gatsby-source-filesystem`,
        options: {
          name: `images`,
          path: `${__dirname}/src/images`,
        },
      },
      {
        resolve: `gatsby-source-filesystem`,
        options: {
          name: `src`,
          path: `${__dirname}/src/`,
        },
      },
      `gatsby-transformer-sharp`,
      `gatsby-transformer-remark`,
      `gatsby-plugin-sharp`,
      {
        resolve: `gatsby-plugin-manifest`,
        options: {
          name: `gatsby-starter-default`,
          short_name: `starter`,
          start_url: `/`,
          background_color: `#663399`,
          theme_color: `#663399`,
          display: `minimal-ui`,
          icon: `src/images/gatsby-icon.png`, // This path is relative to the root of the site.
        },
      },
      `gatsby-plugin-netlify-cms`,
      // this (optional) plugin enables Progressive Web App + Offline functionality
      // To learn more, visit: https://gatsby.dev/offline
      // 'gatsby-plugin-offline',
    ],
  }
  </code></pre>
  
  <p>I can't, for the life of me, figure out why this doesn't work. </p>
  
  <p>I tried the exact tutorial in the Sourcing from NetlifyCMS doc and got that working. I'm not sure why/where/how my attempt to add netlifyCMS to the default Gatsby starter is failing...</p>
  
  <p><a href="https://i.stack.imgur.com/hPYww.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hPYww.png" alt="enter image description here"></a></p>