Problem

iOS device tests were experiencing random failures on CI where apps fail to start after installation with xharness:

error HE0042: Could not launch the app 'com.microsoft.maui.essentials.devicetests' on the device 'iOS 18.5 (22F77) - iPhone Xs': simctl returned exit code 4
dbug: Underlying error (domain=FBSOpenApplicationServiceErrorDomain, code=4):
dbug: The request to open "com.microsoft.maui.essentials.devicetests" failed.

These failures were intermittent - the same CI machines could have both successful and failed runs, indicating timing and resource-related issues rather than fundamental problems.

Root Cause

The failures occurred due to:

1. Insufficient launch timeout: 6 minutes wasn't adequate for problematic CI conditions
2. Lack of targeted retry logic: Retries existed at test category level but not specifically for app launch failures
3. Missing pipeline safety net: iOS tests lacked the retryCountOnTaskFailure configuration that Android/Windows had
4. Poor error differentiation: Launch failures weren't distinguished from test execution failures

Solution

1. Dynamic Launch Timeout Configuration

• Local builds: 6 minutes (unchanged)
• CI builds: 10 minutes (increased from 6 minutes)

var launchTimeout = IsCIBuild() ? "00:10:00" : "00:06:00";

2. Intelligent Launch Failure Detection

Added IsSimulatorLaunchFailure() function to specifically detect launch failures:

bool IsSimulatorLaunchFailure(Exception ex)
{
    var message = ex.Message;
    return message.Contains("simctl returned exit code 4") || 
           message.Contains("HE0042") ||
           message.Contains("Could not launch the app") ||
           message.Contains("FBSOpenApplicationServiceErrorDomain") ||
           message.Contains("Simulator device failed to launch");
}

3. Enhanced Retry Logic

• Detects launch failures specifically
• Adds 5-second delay between retries for launch failures to let simulator settle
• Provides better logging for debugging

4. Pipeline-Level Safety Net

Added iOS to platforms that get retryCountOnTaskFailure: 1 (was missing compared to Android/Windows).

Impact

• Improved Reliability: Multiple layers of resilience for launch failures
• Better Debugging: Enhanced logging helps identify root causes
• Minimal Overhead: Changes only affect problematic scenarios
• Consistent Behavior: iOS now matches Android/Windows retry behavior

Validation

• ✅ Cake script compilation tests pass
• ✅ Launch failure detection unit tests pass
• ✅ YAML syntax validation passes
• ✅ Minimal code changes (31 lines added, 4 removed across 3 files)
• ✅ No breaking changes to existing functionality

The fix provides multiple safety nets while maintaining backward compatibility and addressing the intermittent nature of the simulator launch issues.

Fixes #30795.

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