Increase JavaScript Heap size in create-react-app project

"build": "react-scripts --max_old_space_size=4096 build"

This should work

Thanks a lot to @dan-abramov as his comment is the answer! (Give him the vote up in case you come across this).

You can just put e.g. node --max_old_space_size=4096 node_modules/.bin/react-scripts start in there instead of react-scripts start