"An Unknown error occurred" When trying to launch my Siri Shortcut

Question

I am adding siri Shortcuts to my existing app. There are three shortcuts, one to start the app with a specific value, one to increase the value by an amount and one to decrease the value by an amount. The shortcut code, for the start the app is attached here:

//
//  StartMeetingIntentHandler.swift
//


import Intents
import SwiftUI

class StartMeetingIntentHandler: NSObject, StartMeetingIntentHandling {


    @ObservedObject var meeting = Meeting()

    func handle(intent: StartMeetingIntent, completion: @escaping (StartMeetingIntentResponse) -> Void) {
        if let attendees = intent.attendees {
            meeting.meetingStarted()
            meeting.addAttendee(numberToAdd: Int(truncating: attendees))
            completion(StartMeetingIntentResponse.success(result: attendees))
        } else {
            print("failure")
        }
    }

    func resolveAttendees(for intent: StartMeetingIntent, with completion: @escaping (StartMeetingAttendeesResolutionResult) -> Void) {
        let people = Int(truncating: intent.attendees ?? 0)
        if people < 0 {
            completion(StartMeetingAttendeesResolutionResult.unsupported(forReason: StartMeetingAttendeesUnsupportedReason.negativeNumbersNotSupported))
        } else if people > 1000 {
            completion(StartMeetingAttendeesResolutionResult.unsupported(forReason: StartMeetingAttendeesUnsupportedReason.greaterThanMaximumValue))
        } else {
            completion(StartMeetingAttendeesResolutionResult.success(with: people))
        }
    }
}

When I run the shortcut from the Shortcuts app, I get the message "An unknown error has occurred". How does one go about debugging that?

After reviewing the console for the simulator I found two errors: 1)

[INCExtensionRequest _extensionContextHost] Unexpected extension context class (null)

and 2)

-[WFAction runWithInput:userInterface:parameterInputProvider:variableSource:completionHandler:]_block_invoke Action <WFHandleCustomIntentAction: 0x7ffe845b1a10, identifier: com.theapapp.wastedtime.AddAttendeeIntent, parameters: 2> finished with error {domain: WFIntentExecutorErrorDomain, code: 103}. Error Domain=WFIntentExecutorErrorDomain Code=103 "An unknown error occurred." UserInfo={NSLocalizedDescription=An unknown error occurred., WFIntentExecutorIntentResponseErrorKey=<INIntentResponse: 0x600003f63f80> {
    userActivity = <null>;
    code = INIntentResponseCodeFailure;
}, WFIntentExecutorIntentErrorKey=<INIntent: 0x6000018f0630> {
    people = 1;
}, NSLocalizedFailureReason=Could Not Run Add Attendee}

Answer 1

I had this exact same error because I was accidentally returning my CustomIntent instead of my CustomIntentHandler in the IntentHandler.swift file

Before:

class IntentHandler: INExtension {
    override func handler(for intent: INIntent) -> Any {
        if intent is CustomIntent {
          return CustomIntent()
        }
        return self
    }
}

After:

class IntentHandler: INExtension {
    override func handler(for intent: INIntent) -> Any {
        if intent is CustomIntent {
          return CustomIntentHandler()
        }
        return self
    }
}