<document source="test data">
    <section ids="perl-test-of-source-and-lineno" names="perl test of $source and $lineno">
        <title>
            Perl Test of $SOURCE and $LINENO
        <system_message level="1" line="4" source="test data" type="INFO">
            <paragraph>
                No directive entry for "perl" in module "Text::Restructured::Directive".
                Trying "perl" as canonical directive name.
        <paragraph>
            This directive was called from test data, 4
        <paragraph>
            A paragraph.
