How to enable php error display in shopware 6?

How to enable php error display in shopware 6?

I got the following message when php error occurs but not showing the php error?

Unfortunately, something went wrong.

Hey,

is your APP_ENV in .env set to dev?

Shopware 6 is a Symfony application, so make sure to place a twig.yaml in your config folder with 

twig:
    debug: '%kernel.debug%'
    strict_variables: false
    cache: false

This should enable the debug mode.

But: Because you’re getting no error - Don’t you use the development github version for development?