Using Activity.RecordException now correctly updates the error status of OpenTelemetry Spans

[jamescrosswell]

Fixes #2514

Problem

When users of our OpenTelemetry integration catch errors and record these using Activity.RecordException (vs using SentrySdk.CatpureException) the span that gets created in Sentry is not correctly categorised as an error span and doesn't have stack trace information etc.

Solution

When exceptions capturing is instrumented this way, the OpenTelemetry .NET SDK currently doesn't provide access to the original exception, so we can't get as much information as we could via SentrySdk.CatpureException but we can recreate a synthetic exception that includes some of the original exception details and ensures the Span that we record in Sentry shows correctly as errored.

The OpenTelemetry .NET SDK provides us with the exception type, message and a "stack trace" (which is Exception.ToString()) that might look something like this:

Program+MyException: Attempted to divide by zero.
    ---> System.DivideByZeroException: Attempted to divide by zero.
    at Program.Main()
    --- End of inner exception stack trace ---
    at Program.Main()   

For something like an AggregateException that stack trace would look more complicated.

It might be possible to parse this into an exception graph that could be then be used in our MainExceptionProcessor to create one or more SentryExceptions. However it probably makes more sense to push to get the underlying issue in the Otel codebase resolved instead.

For the time being, we're just putting the stack trace provided by OpenTelemetry in an otel.stack_trace attribute that gets sent with the event for the exception. So people can see the stack trace provided by OpenTelemetry if they want.

[bitsandfoxes]

The PR looks good to me. The TODO here sounds like quite the gotcha.

[jamescrosswell]

It does. It occurs if you do something like this:

        using var activity = Telemetry.ActivitySource.StartActivity("Funny business");
        try
        {
            throw new Exception("test activity.RecordException");
        }
        catch (Exception e)
        {
            SentrySdk.CaptureException(e);
            activity?.RecordException(e);
            activity?.SetStatus(Status.Error.WithDescription(e.Message));
        }
        return "Catch";

The deduplication doesn't work at all (since it matches by reference). Again, we could come up with convoluted ways of working around this but I think the ultimate solution is to address the issue in the OpenTelemetry codebase rather than try to work around it in ours.

I'll create an issue for the above in our repository saying as much though.

[jamescrosswell]

#2519

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

- Using `Activity.RecordException` now correctly updates the error status of OpenTelemetry Spans ([#2515](https://github.com/getsentry/sentry-dotnet/pull/2515))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description.

Generated by 🚫 dangerJS against 38ae2bf