Webpack bundle for server side execution not working with superagent

I get warnings while bundling and a crash when running a webpack bundle with target ‘node’.

webpack.config.js:

export default {
    name: 'server',
    target: 'node',
    ...
}

Bundling warnings:

WARNING in ./~/superagent/~/formidable/lib/incoming_form.js
Critical dependencies:
3:43-50 require function is used in a way in which dependencies cannot be statically extracted
 @ ./~/superagent/~/formidable/lib/incoming_form.js 3:43-50

WARNING in ./~/superagent/~/formidable/lib/file.js
Critical dependencies:
3:43-50 require function is used in a way in which dependencies cannot be statically extracted
 @ ./~/superagent/~/formidable/lib/file.js 3:43-50

WARNING in ./~/superagent/~/formidable/lib/json_parser.js
Critical dependencies:
3:43-50 require function is used in a way in which dependencies cannot be statically extracted
 @ ./~/superagent/~/formidable/lib/json_parser.js 3:43-50

WARNING in ./~/superagent/~/formidable/lib/querystring_parser.js
Critical dependencies:
3:43-50 require function is used in a way in which dependencies cannot be statically extracted
 @ ./~/superagent/~/formidable/lib/querystring_parser.js 3:43-50

Crash when bundle is run:

    var fs = require('fs');
             ^
TypeError: undefined is not a function

[tdeheurles]

You can try to fix that issue by adding

plugins: [
    new webpack.DefinePlugin({ "global.GENTLY": false })
],

to your webpack config

[davis]

I got around it by removing some lines from the bundle after building. Inconvenient, but works for now. Thanks though!