.NET Maui iOS: Catch Initialization Error

[Mike-E-angelo]

Hello all,

I recently added a Sentry account to track down an initialization error during application load that (naturally) only occurs in the deployed App Store (Test Flight).

I am trying to log an error locally during initialization, but when I throw the error and call SentrySdk.CaptureException nothing seems to get reported to the dashboard.

Is there another consideration I should be aware of to get logging enabled and sent to my Sentry dashboard?

Thank you for any assistance you can provide.

[Mike-E-angelo]

Looks like I had to do this:

        try
        {
            // initialize
        }
        catch (Exception e)
        {
            using var temp = SentrySdk.Init(dsn);
            var       id = SentrySdk.CaptureException(e); // Explicitly capture the exception
            throw;
        }

[jamescrosswell]

Thanks @Mike-E-angelo - that makes sense... Sentry won't be able to catch exceptions before it's initialised 😜

Nice workaround!

[Mike-E-angelo]

Sure thing, @jamescrosswell. FWIW, from a newbie's perspective, since you do everything else so amazingly and magic-like, the expectation is that you would be doing this behind the scenes from the outset. For instance, products such as Serilog have an initialization logger where events are routed through during application setup. It was surprising not to see this in your otherwise outstandingly impressive product. To add to the pain, there doesn't seem to be any documentation dedicated to this rather common scenario. This resulted in this discussion that was created here. Thank you for any consideration toward improving this experience. 🙏

[jamescrosswell]

Thanks for the kind words @Mike-E-angelo!

I'm not sure there's anything we can do in this particular case though. The SDK can't register hooks for unhandled exceptions or otherwise catch errors before/until it has been initialised...

About the only thing I can think of is that we could potentially add your workaround above to the troubleshooting docs or to a sample somewhere.

[Mike-E-angelo]

Thank you for the continued dialogue @jamescrosswell. 🙏

The SDK can't register hooks for unhandled exceptions or otherwise catch errors before/until it has been initialised

Maybe not for the long-lived primary application, but the idea here is to register a temporarily initialized SDK during initialization and then dispose of it once the application is built.

So:

1. After UseSentry, a call is made to SentrySdk.Init and storing this IDisposable in a global/static variable
2. Calls are made to TaskScheduler.UnobservedTaskException and AppDomain.CurrentDomain.UnhandledException (or equivalents, depending on context) to register delegates in the case of uncaught exceptions during initialization only
3. If an exception is thrown to the above handlers during initialization, check if the IDisposable created in step 1 is available and report accordingly. The IDisposable is additionally disposed of if found.
4. Once the application is built successfully and the new long-lived initialized SDK is created, dispose of the temporary IDisposable and clear the registrations of step 2.

Please let me know if I have fundamentally misunderstood something along the way here.

About the only thing I can think of is that we could potentially add your workaround above to the troubleshooting docs or to a sample somewhere.

This would also be a welcome first step. 😊🙏

[jamescrosswell]

Added an issue for this:

• Document how to catch errors during initialisation #4463