In development environment, laravel generates lots of error logs in storage directory as files named according to dates, for example 2019–08–15.log so to write those In linux distros like Ubuntu, we need to give Super User permission to storage directory.
sudo chmod -R 776 /storage
Same way for bootstrap directory we often get error like this. Hence best practice in would be to give both of these directories access to write.
sudo chmod -R 776 /bootstrap /storage