// Stacktrace
System.ArgumentNullException
Value cannot be null.
Parameter name: element
   at System.Attribute.GetCustomAttributes(Assembly element, Type attributeType, Boolean inherit)
   at System.Reflection.CustomAttributeExtensions.GetCustomAttributes[T](Assembly element)
   at CommandLine.Infrastructure.ReflectionHelper.GetAttribute[TAttribute]()
   at CommandLine.Text.HelpText.AutoBuild[T](ParserResult`1 parserResult, Func`2 onError, Func`2 onExample, Boolean verbsIndex, Int32 maxDisplayWidth)
   at CommandLine.Text.HelpText.AutoBuild[T](ParserResult`1 parserResult, Int32 maxDisplayWidth)
   at CommandLine.Parser.<>c__DisplayClass17_0`1.<DisplayHelp>b__1(IEnumerable`1 _, TextWriter writer)
   at CSharpx.MaybeExtensions.Do[T1,T2](Maybe`1 maybe, Action`2 action)
   at CommandLine.ParserResultExtensions.WithNotParsed[T](ParserResult`1 result, Action`1 action)
   at CommandLine.Parser.DisplayHelp[T](ParserResult`1 parserResult, TextWriter helpWriter, Int32 maxDisplayWidth)
   at Program.<Main>d__5.MoveNext() in C:\..\..\Program.cs:line 33

// Test method (xUnit) which fails
[Fact]
public async Task CallMain_GiveHelpArgument_ExpectSuccess() {
    var result = await Program.Main(new[] { "--help" });

    Assert.Equal(ERROR_SUCCESS, result);
}

// main program
internal class Program {

  private const int ERROR_SUCCESS = 0;

  internal static async Task<int> Main(string[] args) {
      bool hasError = false;
      bool helpOrVersionRequested = false;

      ParserResult<Options> parsedOptions = Parser.Default.ParseArguments<Options>(args).WithNotParsed(errors => {
          helpOrVersionRequested = errors.Any(x => x.Tag == ErrorType.HelpRequestedError || x.Tag == ErrorType.VersionRequestedError);
          hasError = true;
      });

      if (helpOrVersionRequested) {
          return ERROR_SUCCESS;
      }

    // Execute as a normal call
    // ...
  }
  
}

// Options
internal class Options {

  [Option('c', "connectionString", Required = true, HelpText = Texts.ExplainConnection)]
  public string ConnectionString { get; set; }

  [Option('j', "jobId", Required = true, HelpText = Texts.ExplainJob)]
  public int JobId { get; set; }

  [Usage(ApplicationAlias = "Importer.exe")]
  public static IEnumerable<Example> Examples {
      get => new[] {
          new Example(Texts.ExplainExampleExecution, new Options() {
              ConnectionString="Server=MyServer;Database=MyDatabase",
              JobId = 5
          }),
      };
  }

}