Failed to change icon: The operation couldn’t be completed. Resource temporarily unavailable

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Summary

The error “Failed to change icon: The operation couldn’t be completed. Resource temporarily unavailable” occurs when attempting to change the app icon using UIApplication.shared.setAlternateIconName. This issue is often encountered in Swift and SwiftUI applications. The root cause of this problem lies in the way the icon change operation is handled, particularly when the resource is temporarily unavailable.

Root Cause

The root cause of this issue is due to the following reasons:

  • The icon change operation is not properly synchronized, leading to conflicts when multiple requests are made simultaneously.
  • The resource required for the icon change operation is temporarily unavailable, causing the operation to fail.
  • The error handling mechanism is not robust, failing to provide a clear indication of the cause of the failure.

Why This Happens in Real Systems

This issue occurs in real systems due to the following factors:

  • Concurrent requests: When multiple requests are made to change the icon simultaneously, it can lead to conflicts and cause the operation to fail.
  • Resource constraints: When the resource required for the icon change operation is temporarily unavailable, it can cause the operation to fail.
  • Poor error handling: If the error handling mechanism is not robust, it can fail to provide a clear indication of the cause of the failure, making it difficult to diagnose and resolve the issue.

Real-World Impact

The real-world impact of this issue includes:

  • Poor user experience: The failure to change the icon can lead to a poor user experience, causing frustration and dissatisfaction among users.
  • Increased support requests: The issue can lead to an increase in support requests, causing additional workload and costs for the support team.
  • Negative reviews: The issue can lead to negative reviews and ratings, causing damage to the reputation of the application and the company.

Example or Code

// Determine the correct icon name to pass
let iconToSet: String? = (iconName == "AppIcon") ? nil : iconName

// Only attempt change if it’s different from current icon
if UIApplication.shared.supportsAlternateIcons, UIApplication.shared.alternateIconName != iconToSet {
    UIApplication.shared.setAlternateIconName(iconToSet) { error in
        if let error = error {
            print("Failed to change icon:", error.localizedDescription)
            HapticManager.shared.error()
        } else {
            print("Icon change requested successfully")
            HapticManager.shared.medium()
            // Update selectedIcon on main thread
            DispatchQueue.main.async {
                selectedIcon = iconName
            }
        }
    }
} else {
    print("Icon already selected or alternate icons not supported")
}

How Senior Engineers Fix It

Senior engineers fix this issue by:

  • Implementing proper synchronization mechanisms to ensure that only one icon change operation is executed at a time.
  • Handling errors robustly, providing clear indications of the cause of the failure and implementing retry mechanisms to handle temporary resource unavailability.
  • Optimizing resource usage, ensuring that the resource required for the icon change operation is available when needed.

Why Juniors Miss It

Junior engineers may miss this issue due to:

  • Lack of experience with concurrent programming and resource management.
  • Insufficient understanding of the icon change operation and its dependencies.
  • Inadequate testing, failing to simulate scenarios that can lead to the resource being temporarily unavailable.