php artisan not displaying anything

I've been battling with this for a while and in one scenerio the only way around this issue was to replace the vendors folder with another pc's vendors.

The situation is that "php artisan" returns nothing. I've got error_log set to output an error file, and I've ensured that file is writable by all users. This is the full php.ini file, which has been confirmed to being loaded:

display_errors = 1 error_log = "/var/www/errors.log" error_reporting = "E_ALL"

I can't understand why no errors are displaying or being saved, or why artisan doesn't display anything.

I've even changed permissions on the entire site to 777 (for interest), and still nothing.

Has anyone had the same experience?

(Where using a docker image configure to load php 7.1)