Mis-typed CommandLine.BaseAttribute.Default results in ArgumentException: Object of type 'X' cannot be converted to type 'Y'

[ohadschn]

The following:

class MyOptions
{
    public MyOptions(string foo) {Foo = foo;}

    [Option("foo", Required = false, Default = 42)] //note the integer default
    public string Foo {get;} 
}

Will result in:

System.ArgumentException: Object of type 'System.Int32' cannot be converted to type 'System.String'.
   at System.RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast)
   at System.RuntimeType.CheckValue(Object value, Binder binder, CultureInfo culture, BindingFlags invokeAttr)
   at System.Reflection.MethodBase.CheckArguments(Object[] parameters, Binder binder, BindingFlags invokeAttr, CultureInfo culture, Signature sig)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at CommandLine.Core.InstanceBuilder.<>c__DisplayClass0_2`1.<Build>b__23()
   at CommandLine.Core.InstanceBuilder.<>c__DisplayClass0_0`1.<Build>b__7()
   at CommandLine.Core.InstanceBuilder.Build[T](Maybe`1 factory, Func`3 tokenizer, IEnumerable`1 arguments, StringComparer nameComparer, Boolean ignoreValueCase, CultureInfo parsingCulture, IEnumerable`1 nonFatalErrors)
   at CommandLine.Core.InstanceChooser.MatchVerb(Func`3 tokenizer, IEnumerable`1 verbs, IEnumerable`1 arguments, StringComparer nameComparer, CultureInfo parsingCulture, IEnumerable`1 nonFatalErrors)
   at CommandLine.Core.InstanceChooser.<>c__DisplayClass0_0.<Choose>b__0()
   at CommandLine.Core.InstanceChooser.Choose(Func`3 tokenizer, IEnumerable`1 types, IEnumerable`1 arguments, StringComparer nameComparer, CultureInfo parsingCulture, IEnumerable`1 nonFatalErrors)
   at CommandLine.Parser.ParseArguments(IEnumerable`1 args, Type[] types)
   at CommandLine.ParserExtensions.ParseArguments[T1,T2](Parser parser, IEnumerable`1 args)
   at CommandLineParserTest.Program.Main()

A more meaningful exception would go a long way to help debugging such issues.

[moh-hassan]

It's resolved in v2.5.0