Why does using --help do this?

Out of interest now when I use --help I get the help listed twice:

C:\Program Files (x86)\Meeting Schedule Assistant\OutlookCalIFConsole>outlookcalifconsole --help
OutlookCalIFConsole 2018.4.4.1
Copyright c  2017 - 2018

  -l, --list          Builds a list of available calendars. Eg: -l ".\CalendarList.xml"

  -m, --mode          Type of events to add to the calendar. Modes: mwb. Eg: -m mwb

  -p, --path          Path to the events data file. Eg: -p ".\EventsToAdd.xml"

  -t, --tokencache    Required. The location of the token cache data file. Eg: -t "file.dat"

  -e, --errorlog      Required. The location for the error log. Eg: -e "<path to error folder>"

  -s, --signout       Sign out from Outlook calendar

  --help              Display this help screen.

  --version           Display version information.

OutlookCalIFConsole 2018.4.4.1
Copyright c  2017 - 2018

  -l, --list          Builds a list of available calendars. Eg: -l
                      ".\CalendarList.xml"

  -m, --mode          Type of events to add to the calendar. Modes: mwb. Eg: -m
                      mwb

  -p, --path          Path to the events data file. Eg: -p ".\EventsToAdd.xml"

  -t, --tokencache    Required. The location of the token cache data file. Eg:
                      -t "file.dat"

  -e, --errorlog      Required. The location for the error log. Eg: -e "<path
                      to error folder>"

  -s, --signout       Sign out from Outlook calendar

  --help              Display this help screen.

  --version           Display version information.

Why might this be? If I use --version it is not listed twice.

I am using standard code to build the help:

        static int Main(string[] args)
        {
            var parserResult = CommandLine.Parser.Default.ParseArguments<Options>(args);

            parserResult.WithParsed<Options>(options => OnSuccessfulParse(options));
            parserResult.WithNotParsed<Options>(errs =>
            {
                var helpText = HelpText.AutoBuild(parserResult, h =>
                {
                    return HelpText.DefaultParsingErrorsHandler(parserResult, h);
                }, e =>
                {
                    return e;
                });
                Console.WriteLine(helpText);
                ReturnErrorCode = ErrorCode.CommandLineArguments;
            });

            return (int)ReturnErrorCode;
        }

Also, why doesn’t the default help keyword have a short version of h?

Looking here:

       /// <summary>
        /// Creates a new instance of the <see cref="CommandLine.Text.HelpText"/> class,
        /// automatically handling verbs or options scenario.
        /// </summary>
        /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
        /// <param name="maxDisplayWidth">The maximum width of the display.</param>
        /// <returns>
        /// An instance of <see cref="CommandLine.Text.HelpText"/> class.
        /// </returns>
        /// <remarks>This feature is meant to be invoked automatically by the parser, setting the HelpWriter property
        /// of <see cref="CommandLine.ParserSettings"/>.</remarks>
        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplayWidth = DefaultMaximumLength)
        {
            if (parserResult.Tag != ParserResultType.NotParsed)
                throw new ArgumentException("Excepting NotParsed<T> type.", "parserResult");

            var errors = ((NotParsed<T>)parserResult).Errors;

            if (errors.Any(e => e.Tag == ErrorType.VersionRequestedError))
                return new HelpText(HeadingInfo.Default){MaximumDisplayWidth = maxDisplayWidth }.AddPreOptionsLine(Environment.NewLine);

            if (!errors.Any(e => e.Tag == ErrorType.HelpVerbRequestedError))
                return AutoBuild(parserResult, current => DefaultParsingErrorsHandler(parserResult, current), e => e, maxDisplayWidth: maxDisplayWidth);

            var err = errors.OfType<HelpVerbRequestedError>().Single();
            var pr = new NotParsed<object>(TypeInfo.Create(err.Type), Enumerable.Empty<Error>());
            return err.Matched
                ? AutoBuild(pr, current => DefaultParsingErrorsHandler(pr, current), e => e, maxDisplayWidth: maxDisplayWidth)
                : AutoBuild(parserResult, current => DefaultParsingErrorsHandler(parserResult, current), e => e, true, maxDisplayWidth);
        }

It seems to me that it itself calls DefaultParsingErrorsHandler. Yet in my code it looks like we do it again. Is this a mistake in my code or something?

[Sire]

Nulling the HelpWriter works: var parserResult = new Parser(with => with.HelpWriter = null).ParseArguments<Options>(args); Instead of: var parserResult = CommandLine.Parser.Default.ParseArguments<Options>(args);

[ArthurAttout]

Nulling the HelpWriter still shows a default help in my case :

public class Options
{
    [Value(0, MetaName = "instructions", HelpText = "Path to instructions file.")]
    public string InstructionsFilePath { get; set; }
}
var parser = new Parser(with => with.HelpWriter = null);
var parserResult = parser.ParseArguments<Options>(args);
Parser.Default.ParseArguments<Options>(args)
    .WithParsed(_start);

Calling myProgram.exe --help in a CLI returns :

MyProgram 1.0.0.0
Copyright ©  2021

  --help                   Display this help screen.

  --version                Display version information.

  instructions (pos. 0)    Path to instructions file.

While my understanding is that it should print nothing. Tested on 2.8.0