fix: Capture Debug.LogError as message, not exception

[bitsandfoxes]

Depends on getsentry/sentry-dotnet#4681
Resolves #2334

Problem

The UnityApplicationLoggingIntegration receives stringified stack traces from Unity for log messages. The SDK automatically captures Debug.LogError events when CaptureLogErrorEvents is enabled. Previously, when AttachStacktrace was enabled, the SDK created a synthetic UnityErrorLogException to attach the stack trace to these events, which would then be processed as a normal exception.

This approach caused several issues:

• Incorrect event type: Debug.LogError messages appeared as exceptions on the Sentry dashboard, not as error messages
• Misleading severity: Issues were sometimes marked as fatal when they were just error logs

Proposal

Debug.LogError events are now captured as message events with stack traces attached via the SentryThreads property, following the same pattern as the MainEventProcessor uses (see here) for regular messages with AttachStacktrace enabled.

Result

[bitsandfoxes]

These are not new tests. The parsing was already tested in the UnityLogExceptionTests and now moved into the helper.

[sentry]

Bug: UnityLogEventFactory.CreateExceptionEvent() misses Terminal = false for Mechanism, affecting Debug.LogError on WebGL.
_{Severity: HIGH | Confidence: 0.95}

🔍 Detailed Analysis

The UnityLogEventFactory.CreateExceptionEvent() method omits Terminal = false when setting the Mechanism property. This occurs when exceptions are captured from Debug.LogError on WebGL, as CreateExceptionEvent() is still used in this scenario. The absence of Terminal = false means these exceptions will incorrectly mark Sentry sessions as crashed, violating the documented and established behavior for non-terminal log exceptions.

💡 Suggested Fix

Add Terminal = false to the Mechanism object within UnityLogEventFactory.CreateExceptionEvent() to ensure exceptions from Debug.LogError are correctly marked as non-terminal, aligning with established behavior.

🤖 Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: src/Sentry.Unity/SentryUnityOptions.cs#L346

Potential issue: The `UnityLogEventFactory.CreateExceptionEvent()` method omits
`Terminal = false` when setting the `Mechanism` property. This occurs when exceptions
are captured from `Debug.LogError` on WebGL, as `CreateExceptionEvent()` is still used
in this scenario. The absence of `Terminal = false` means these exceptions will
incorrectly mark Sentry sessions as crashed, violating the documented and established
behavior for non-terminal log exceptions.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[cursor]

Bug: Bug

The IL2CPP processor now attempts to process synthetic exceptions created by UnityLogEventFactory.CreateExceptionEvent. The incomingException for these is a simple Exception(message) lacking native IL2CPP metadata, causing incorrect or empty stack traces. This also creates an inconsistency between incomingException and the synthetic SentryException (with unity.log mechanism) in sentryEvent.SentryExceptions.

src/Sentry.Unity/Il2CppEventProcessor.cs#L24-L39

sentry-unity/src/Sentry.Unity/Il2CppEventProcessor.cs

Lines 24 to 39 in b608e71

	// We're throwing here but this should never happen. We're validating UnityInfo before adding the processor.
	_il2CppMethods = UnityInfo.Il2CppMethods ?? throw new ArgumentNullException(nameof(UnityInfo.Il2CppMethods),
	"Unity IL2CPP methods are not available.");
	Options.SdkIntegrationNames.Add("IL2CPPLineNumbers");
	}
	public void Process(Exception incomingException, SentryEvent sentryEvent)
	{
	Options.DiagnosticLogger?.LogDebug("Running Unity IL2CPP event exception processor on: Event {0}", sentryEvent.EventId);
	var sentryExceptions = sentryEvent.SentryExceptions;
	if (sentryExceptions == null)
	{
	return;
	}

src/Sentry.Unity/Integrations/UnityLogEventFactory.cs#L56-L61

sentry-unity/src/Sentry.Unity/Integrations/UnityLogEventFactory.cs

Lines 56 to 61 in b608e71

	return new SentryEvent(new Exception(message))
	{
	SentryExceptions = [sentryException],
	Level = SentryLevel.Error
	};

 

---

Bug: Bug

The DebugLogError_InTask_IsCapturedAndIsMainThreadIsFalse test has issues following the change to capture Debug.LogError events as messages. It incorrectly expects the unity.is_main_thread tag and uses the "value" attribute to identify the message instead of "message", unlike the DebugLogError_IsCaptured test.

test/Sentry.Unity.Tests/IntegrationTests.cs#L241-L248

sentry-unity/test/Sentry.Unity.Tests/IntegrationTests.cs

Lines 241 to 248 in b608e71

	[UnityTest]
	public IEnumerator DebugLogError_InTask_IsCapturedAndIsMainThreadIsFalse()
	{
	if (TestEnvironment.IsGitHubActions)
	{
	Assert.Inconclusive("Flaky"); // Ignoring because of flakiness
	}

 

---