That's because they look for `dist/app.js` but webpack uses `fullhash` in the name, i.e. `dist/app.20fd562f4b5b27e29042.js` https://github.com/Automattic/simplenote-electron/blob/f5d463f7a5f5beb3638696c9700b1c7781448744/Makefile#L21 https://github.com/Automattic/simplenote-electron/blob/f5d463f7a5f5beb3638696c9700b1c7781448744/webpack.config.js#L23