Warning compiling with Webpack 3.8.1

[alasdairhurst]

> webpack

Hash: 31c70c39b24e448aa6bd
Version: webpack 3.8.1
Time: 1570ms
   Asset    Size  Chunks                    Chunk Names
index.js  517 kB       0  [emitted]  [big]  main
   [0] (webpack)/buildin/module.js 495 bytes {0} [built]
   [1] (webpack)/buildin/global.js 488 bytes {0} [built]
   [3] (webpack)/buildin/amd-define.js 85 bytes {0} [built]
   [4] ./node_modules/escodegen/node_modules/source-map/lib/source-map 160 bytes {0} [built]
  [10] ./src/index.js 24.6 kB {0} [built]
  [11] ./src/flowvalidator.js 12.6 kB {0} [built]
  [12] ./src/jsonpath.js 2.37 kB {0} [built]
    + 31 hidden modules

WARNING in ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-map-generator.js
8:45-52 Critical dependency: require function is used in a way in which dependencies cannot be statically extracted
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-map-generator.js
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map.js
 @ ./node_modules/escodegen/escodegen.js
 @ ./node_modules/static-eval/index.js
 @ ./node_modules/jsonpath/lib/handlers.js
 @ ./node_modules/jsonpath/lib/index.js
 @ ./node_modules/jsonpath/index.js
 @ ./src/jsonpath.js
 @ ./src/flowvalidator.js
 @ ./src/index.js

WARNING in ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-map-consumer.js
8:45-52 Critical dependency: require function is used in a way in which dependencies cannot be statically extracted
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-map-consumer.js
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map.js
 @ ./node_modules/escodegen/escodegen.js
 @ ./node_modules/static-eval/index.js
 @ ./node_modules/jsonpath/lib/handlers.js
 @ ./node_modules/jsonpath/lib/index.js
 @ ./node_modules/jsonpath/index.js
 @ ./src/jsonpath.js
 @ ./src/flowvalidator.js
 @ ./src/index.js

WARNING in ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-node.js
8:45-52 Critical dependency: require function is used in a way in which dependencies cannot be statically extracted
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map/source-node.js
 @ ./node_modules/escodegen/node_modules/source-map/lib/source-map.js
 @ ./node_modules/escodegen/escodegen.js
 @ ./node_modules/static-eval/index.js
 @ ./node_modules/jsonpath/lib/handlers.js
 @ ./node_modules/jsonpath/lib/index.js
 @ ./node_modules/jsonpath/index.js
 @ ./src/jsonpath.js
 @ ./src/flowvalidator.js
 @ ./src/index.js

webpack config

const path = require('path');

module.exports = {
	entry: './src/index.js',
	output: {
		filename: 'index.js',
		path: path.resolve(__dirname, 'dist', 'web'),
		libraryTarget: 'commonjs2'
	},
	node: {
		fs: 'empty'
	},
	module: {
		rules: [
			{
				test: /\.(js|jsx)$/,
				loader: 'babel-loader',
				exclude: /node_modules/
			},
			{
				test: /\.json$/,
				loader: 'json-loader'
			}
		]
	}
};

This warning goes away when I manually install the latest escodegen as a dependency in my project, but the ``npm ls``` tree is identical before and after which is kinda strange.