print_test_result's definition is

function print_test( $p_test_description, $p_result, $p_hard_fail=true, $p_message='' )

However, line 154 of admin/install.php calls print_test_result as follows:

print_test_result( BAD, 'Upgrade the version of PHP to a more recent version' );

I think this should actually be

print_test_result( BAD, true, 'Upgrade the version of PHP to a more recent version' );