Fatal error: Uncaught TypeError: call_user_func(): Argument #1 ($callback) must be a valid callback, function "a" not found or invalid function name in /in/cn6vN:8
Stack trace:
#0 {main}
thrown in /in/cn6vN on line 8
Process exited with code 255.
Output for 8.0.0 - 8.0.9
Fatal error: Uncaught TypeError: call_user_func(): Argument #1 ($function) must be a valid callback, function "a" not found or invalid function name in /in/cn6vN:8
Stack trace:
#0 {main}
thrown in /in/cn6vN on line 8
Process exited with code 255.