gatsby: [v2] gatsby - Duplicate styles when serving site

Description

Seeing duplicate style declarations when serving the site.

Not sure if this is a webpack issue or not?

Steps to reproduce

• Repo - https://github.com/imshuffling/davidrich.es
• Running gatsby serve
• Inspect on the console to see duplicated styles declarations, as per screenshot below.

Environment

System: OS: macOS High Sierra 10.13.5 CPU: x64 Intel® Core™ i5-6267U CPU @ 2.90GHz Shell: 5.3 - /bin/zsh Binaries: Node: 9.2.0 - ~/.nvm/versions/node/v9.2.0/bin/node Yarn: 1.6.0 - ~/.nvm/versions/node/v9.2.0/bin/yarn npm: 5.8.0 - ~/.nvm/versions/node/v9.2.0/bin/npm Browsers: Chrome: 68.0.3440.106 Firefox: 60.0.2 Safari: 11.1.1 npmPackages: gatsby: next => 2.0.0-rc.0 gatsby-image: next => 2.0.0-rc.0 gatsby-plugin-catch-links: next => 2.0.2-rc.0 gatsby-plugin-manifest: next => 2.0.2-rc.0 gatsby-plugin-netlify: next => 2.0.0-rc.0 gatsby-plugin-nprogress: next => 2.0.0-rc.0 gatsby-plugin-offline: next => 2.0.0-rc.0 gatsby-plugin-react-helmet: next => 3.0.0-rc.0 gatsby-plugin-sass: next => 2.0.0-rc.0 gatsby-plugin-sharp: next => 2.0.0-rc.0 gatsby-source-contentful: next => 2.0.1-rc.0 gatsby-transformer-remark: next => 2.1.1-rc.0 gatsby-transformer-sharp: next => 2.1.1-rc.0 npmGlobalPackages: gatsby-cli: 1.1.58

File contents (if changed)

gatsby-config.js:

module.exports = {
  siteMetadata: {
    title: `davidrich.es`,
  },
  plugins: [
    `gatsby-plugin-react-helmet`,
    `gatsby-plugin-sass`,
    `gatsby-transformer-remark`,
    `gatsby-plugin-catch-links`,
    `gatsby-transformer-sharp`,
    `gatsby-plugin-sharp`,
    {
      resolve: `gatsby-plugin-manifest`,
      options: {
        name: "David Riches 🏑",
        short_name: "DR 🏑",
        start_url: "/",
        background_color: "#ffffff",
        theme_color: "#A864A8",
        display: "minimal-ui",
        icons: [
          {
            src: `/favicons/android-chrome-192x192.png`,
            sizes: `192x192`,
            type: `image/png`,
          },
          {
            src: `/favicons/android-chrome-512x512.png`,
            sizes: `512x512`,
            type: `image/png`,
          },
        ],
      },
    },
    `gatsby-plugin-offline`,
      {
        resolve: `gatsby-source-contentful`,
          options: {
            spaceId: `anjlutb8dq3v`,
            accessToken: `4bf9314dc5bdfbf380247aa3ab84d7da0e86d33a6089168eb32558d4f7096cda`
          },
      },
      {
        resolve: `gatsby-plugin-netlify`,
          options: {
            headers: {}, // option to add more headers. `Link` headers are transformed by the below criteria
            allPageHeaders: [], // option to add headers for all pages. `Link` headers are transformed by the below criteria
            mergeSecurityHeaders: true, // boolean to turn off the default security headers
            mergeLinkHeaders: true, // boolean to turn off the default gatsby js headers
            mergeCachingHeaders: true, // boolean to turn off the default caching headers
            transformHeaders: (headers, path) => headers, // optional transform for manipulating headers under each path (e.g.sorting), etc.
            generateMatchPathRewrites: true, // boolean to turn off automatic creation of redirect rules for client only paths
        },
      },
  ],
}

package.json:

{
  "name": "gatsby-starter-default",
  "description": "Gatsby default starter",
  "version": "1.0.0",
  "author": "Kyle Mathews <mathews.kyle@gmail.com>",
  "dependencies": {
    "gatsby": "next",
    "gatsby-image": "next",
    "gatsby-plugin-catch-links": "next",
    "gatsby-plugin-manifest": "next",
    "gatsby-plugin-netlify": "next",
    "gatsby-plugin-nprogress": "next",
    "gatsby-plugin-offline": "next",
    "gatsby-plugin-react-helmet": "next",
    "gatsby-plugin-sass": "next",
    "gatsby-plugin-sharp": "next",
    "gatsby-source-contentful": "next",
    "gatsby-transformer-remark": "next",
    "gatsby-transformer-sharp": "next",
    "node-sass": "^4.9.0",
    "react": "^16.4.1",
    "react-anchor-link-smooth-scroll": "^1.0.10",
    "react-dom": "^16.4.1",
    "react-helmet": "^5.2.0",
    "typeface-karla": "0.0.54"
  },
  "keywords": [
    "gatsby"
  ],
  "license": "MIT",
  "main": "n/a",
  "scripts": {
    "build": "gatsby build",
    "develop": "gatsby develop",
    "deploy": "gatsby build --prefix-paths && gh-pages -d public",
    "serve": "gatsby serve",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "devDependencies": {
    "gh-pages": "^1.1.0",
    "prettier": "^1.8.2"
  }
}

gatsby-node.js:

const path = require('path')

exports.createPages = ({graphql, actions}) => {
    const {createPage} = actions
    return new Promise((resolve, reject) => {
        const PortfolioPostTemplate = path.resolve('src/templates/portfolio-post.js')
        resolve(
            graphql(`
                {
                    allContentfulPortfolio (limit:100) {
                        edges {
                            node {
                                id
                                slug
                            }
                        }
                    }
                }
            `).then((result) => {
                if (result.errors) {
                    reject(result.errors)
                }
                result.data.allContentfulPortfolio.edges.forEach((edge) => {
                    createPage ({
                        path: edge.node.slug,
                        component: PortfolioPostTemplate,
                        context: {
                            slug: edge.node.slug
                        }
                    })
                })
                return
            })
        )
    })
}

gatsby-browser.js:

require('typeface-karla')

gatsby-ssr.js: N/A