src/System.php
function raiseError($error)
    {
        if (PEAR::isError($error)) {
            $error = $error->getMessage();
        }
        trigger_error($error, E_USER_WARNING);
        return false;
    }
function raiseError($error)
    {
        if (PEAR::isError($error)) {
            $error = $error->getMessage();
        }
        trigger_error($error, E_USER_WARNING);
        return false;
    }
Output errors with PHP trigger_error(). You can silence the errors
with prefixing a "@" sign to the function call: @System::mkdir(..);

@param mixed $error a PEAR error or a string with the error message
@return bool false
@static
@access private