<document source="test data">
    <paragraph>
        Code block that specifies a non-existent file in the :file: option.
    <system_message level="1" line="3" source="test data" type="INFO">
        <paragraph>
            No directive entry for "code_block" in module "Text::Restructured::Directive".
            Trying "code_block" as canonical directive name.
    <parsed_literal xml:space="preserve">
        states: couldn't open input file `nosuchfile.sh': No such file or directory