const webpack = require('@cypress/webpack-preprocessor')

module.exports = (on) => {
  on('file:preprocessor', webpack({
    webpackOptions: {
      resolve: {
        extensions: ['.ts', '.js']
      },
      node: { fs: 'empty', child_process: 'empty', readline: 'empty' },
      module: {
        rules: [
          { test: /\.ts$/, exclude: [/node_modules/], use: [{ loader: 'ts-loader' }] },
          { test: /\.feature$/, use: [{ loader: 'cypress-cucumber-preprocessor/loader' }] },
          { test: /\.features$/, use: [{ loader: 'cypress-cucumber-preprocessor/lib/featuresLoader' }] }
        ]
      }
    }
  }))
}

@@ -605,16 +605,45 @@
 %0A      %7D
+,%0A      devtool: 'source-map'
 %0A    %7D%0A 

Add source maps. It has no effect yet, but you never know...