Reactive-Resume/gatsby-node.js

const MiniCssExtractPlugin = require('mini-css-extract-plugin');

exports.onCreateWebpackConfig = ({ actions, stage, getConfig }) => {
  if (stage === 'build-javascript') {
    const config = getConfig();
    const index = config.plugins.findIndex((plugin) => {
      return plugin.constructor.name === 'MiniCssExtractPlugin';
    });
    config.plugins[index] = new MiniCssExtractPlugin({
      ignoreOrder: true,
    });
    actions.replaceWebpackConfig(config);
  }
};