Fatal error: Uncaught TypeError: Return value of foo() must be an instance of void, none returned in /in/sUR8K:3
Stack trace:
#0 /in/sUR8K(5): foo()
#1 {main}
thrown in /in/sUR8K on line 3
Process exited with code 255.
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.28
Parse error: syntax error, unexpected ':', expecting '{' in /in/sUR8K on line 3
Process exited with code 255.