Why aren't exceptions handled by the Exception middleware

[cartercommunity]

Why aren't exceptions handled by the Exception middleware

[jchannon]

I've added some console.writeline everywhere and its simply not coming back into botwin. If I do the below:

app.UseExceptionHandler("/foo");

app.UseWhen(ctx=>ctx.Request.Path=="/foo", subapp => subapp.Run(ctx=>ctx.Response.WriteAsync("ppppp")));

           
app.UseBotwin(this.GetOptions());

/foo is hit when /error throws an exception

The route handler for /errorhandler is never hit in the sample as it stands

[jchannon]

The issue seems to be adding headers to the request on the exception handler. The sample does this on the Botwin global before hook

https://github.com/aspnet/Diagnostics/blob/dev/src/Microsoft.AspNetCore.Diagnostics/ExceptionHandler/ExceptionHandlerMiddleware.cs#L82

[jchannon]

Issue raised here aspnet/Diagnostics#425