[ERROR] Command “site:install”, is not a valid command name.

If you are getting this error

 [ERROR] Command "site:install", is not a valid command name.

after installing drupal console, it it because you are running the command outside a drupal installation folder. The confusion is the fact that most of us expect a “site:install” to go out and retrieve the drupal files for us but the command is not doing that.

The site:install allows us to install drupal from the command line. 
It DOES NOT retrieve Drupal files for you. 

It took me a while to figure this out.

setgid Permission

When setgid permission is applied to a directory, files that were created in this directory belong to the group to which the directory belongs.

How to set the setgid permission

chmod g+s directory

How to unset the setgid permission

chmod g-s directory