1--TEST-- 2Test that the mixed return type is not compatible with a void return value 3--FILE-- 4<?php 5 6function foo(): mixed 7{ 8} 9 10try { 11 foo(); 12} catch (TypeError $exception) { 13 echo $exception->getMessage() . "\n"; 14} 15 16?> 17--EXPECT-- 18foo(): Return value must be of type mixed, none returned 19