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> Debugging & Testing

// Master debugging techniques and testing strategies for Swift and SwiftUI development. Learn to use Xcode's debugging tools, write effective tests, track crashes, and troubleshoot common issues.

27 Articles

01
June 13, 2026
Fixing "-[OS_dispatch_mach_msg _setContext:]: unrecognized selector" on iOS 27
XcodeiOSDebugging
An app that ran fine for years suddenly hangs on the splash screen when you debug it on an iOS 27 device...
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02
June 9, 2026
How to Export and Use Xcode 27's Agent Skills in Claude Code
XcodeAIClaude-CodeAgent-SkillsSwiftUI
Xcode 27 ships seven official agent skills that capture Apple's own guidance on SwiftUI, testing, and...
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03
June 8, 2026
Fixing "Supported Deployment Target Versions is 15.0 to 27.0" in Xcode 27
XcodeiOSCocoaPodsDebugging
Xcode 27 dropped support for deployment targets below iOS 15. If your build now fails with...
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04
April 6, 2026
Fixing the fmt consteval Error in Xcode 26.4 for React Native
React-NativeXcodeC++
If your React Native build started failing after upgrading to Xcode 26.4 with a consteval error from the fmt...
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05
April 5, 2026
Intercepting Network Requests in Swift with URLProtocol
SwiftURLSessionNetworkingTesting
URLProtocol is one of the oldest interception points in Foundation's networking stack. It lets you mock, log...
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06
April 3, 2026
Structured Logging in Swift with Logger and os_log
SwiftLoggingDebugging
print is fine for scratch work, but production apps need categories, levels, and privacy redaction. Here is...
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07
March 13, 2026
How to Free Up Disk Space Used by Xcode
XcodeDevelopment-EnvironmentmacOS
Xcode can consume 50GB+ of disk space over time. Here's how to reclaim storage by clearing caches, old...
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08
March 12, 2026
Getting Started with Swift Testing: Apple's Modern Test Framework
SwiftTestingXcodeSwift-Testing
Swift Testing replaces XCTest with a cleaner macro-based API. Learn how to write tests with @Test, #expect...
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09
March 11, 2026
Understanding Swift Macros: A Practical Guide
SwiftMacrosAdvancedXcode
Swift macros generate code at compile time, reducing boilerplate and catching errors early. Learn how to use...
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10
March 3, 2026
Auto-Approve the Xcode MCP Connection Prompt with Claude Code Hooks
XcodeAIClaude-CodeDevelopment-Environment
The Xcode MCP server connection prompt interrupts your flow every time you restart Claude Code or clear your...
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11
February 20, 2026
Testing Push Notifications on iOS Simulators with xcrun simctl push
iOSSimulatorPush-NotificationsTestingXcode
Learn how to test push notifications on iOS simulators without needing a device or server setup using xcrun...
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12
February 15, 2026
How to Preview Live Activities in SwiftUI
SwiftUIWidgetKitLive-ActivitiesXcodePreviews
Use the #Preview macro to preview your Live Activity views directly in Xcode without running the full app.
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13
February 12, 2026
Debugging SwiftUI Previews in Xcode
SwiftUIXcodePreviewsDebugging
When SwiftUI previews break, the error messages aren't always helpful. Here's how to debug them, clear...
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14
February 4, 2026
How to Use Xcode's MCP Server to Build Xcode into Your AI Workflow
XcodeAIDevelopment-Environment
Xcode 26.3 ships with a built-in MCP server that exposes project structure, build actions, and test results...
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15
December 10, 2025
Fixing "No Such Module" Errors in Xcode
XcodeSwift-Package-ManagerDebuggingCocoaPods
When Xcode says it can't find a module you've clearly installed, the problem is usually in your build...
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16
December 4, 2025
Simulating Device Conditions in Xcode for Real-World Testing
XcodeTestingPerformanceDevelopment
Learn how to use Xcode's Device Conditions feature to simulate thermal state and network conditions to test...
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17
November 18, 2025
Fixing iOS Simulator That Won't Launch or Boot
XcodeSimulatorDebugging
When the iOS Simulator refuses to launch, gets stuck booting, or shows a black screen, here's how to diagnose...
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18
November 3, 2025
Fixing Xcode Indexing That's Stuck or Slow
XcodePerformanceDebugging
When Xcode's indexing gets stuck or takes forever, your autocomplete and jump-to-definition stop working...
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19
October 8, 2025
Fixing SwiftUI Previews That Won't Load
XcodeSwiftUIDebuggingPreviews
When SwiftUI previews fail with cryptic errors or just spin forever, here's how to diagnose and fix the most...
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20
September 11, 2025
Previewing Partially Generated Content with Foundation Models in SwiftUI
SwiftUIFoundation-ModelsXcodePreviewsAI
When building UIs that stream AI-generated content using Apple's Foundation Models framework, testing...
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21
July 11, 2025
Symbolicating Swift Crash Reports in Xcode
XcodeDebuggingCrash-ReportingProduction
Learn how to symbolicate crash logs from App Store Connect and Xcode Cloud to debug production crashes...
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22
July 2, 2025
How to search SF Symbols in Xcode
XcodeSwiftUIDesign
Learn how to search SF Symbols in Xcode.
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23
April 19, 2025
Inspecting all SwiftUI Environment Values
SwiftUIEnvironmentDebuggingDevelopment
Learn how to dump all SwiftUI environment values for debugging purposes.
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24
March 17, 2025
Firebase Crashlytics dSYM files not uploading using Xcode 15+
FirebaseXcodeCrashlyticsDebugging
Learn how to fix the Firebase Crashlytics dSYM files not properly being uploaded to Firebase after upgrading...
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25
October 8, 2024
Detecting if SwiftUI is running in a Preview in Xcode
SwiftUIXcodePreviewsDevelopment
Learn how to detect if a SwiftUI app is running in a Xcode Preview.
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26
October 8, 2024
Fixing CocoaPods "Unknown ISA PBXFileSystemSynchronizedRootGroup" Error
CocoaPodsXcodeiOSTroubleshooting
How to resolve the pod install error caused by Xcode 16's new folder-based group structure.
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27
November 3, 2022
Ways to Shoot Yourself in the Foot with Method Swizzling
Objective-CRuntimeDebugging
Swizzling is powerful but dangerous. Here are the common pitfalls and how to avoid turning your clever hack...
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> Debugging & Testing

Fixing "-[OS_dispatch_mach_msg _setContext:]: unrecognized selector" on iOS 27

How to Export and Use Xcode 27's Agent Skills in Claude Code

Fixing "Supported Deployment Target Versions is 15.0 to 27.0" in Xcode 27

Fixing the fmt consteval Error in Xcode 26.4 for React Native

Intercepting Network Requests in Swift with URLProtocol

Structured Logging in Swift with Logger and os_log

How to Free Up Disk Space Used by Xcode

Getting Started with Swift Testing: Apple's Modern Test Framework

Understanding Swift Macros: A Practical Guide

Auto-Approve the Xcode MCP Connection Prompt with Claude Code Hooks

Testing Push Notifications on iOS Simulators with xcrun simctl push

How to Preview Live Activities in SwiftUI

Debugging SwiftUI Previews in Xcode

How to Use Xcode's MCP Server to Build Xcode into Your AI Workflow

Fixing "No Such Module" Errors in Xcode

Simulating Device Conditions in Xcode for Real-World Testing

Fixing iOS Simulator That Won't Launch or Boot

Fixing Xcode Indexing That's Stuck or Slow

Fixing SwiftUI Previews That Won't Load

Previewing Partially Generated Content with Foundation Models in SwiftUI

Symbolicating Swift Crash Reports in Xcode

How to search SF Symbols in Xcode

Inspecting all SwiftUI Environment Values

Firebase Crashlytics dSYM files not uploading using Xcode 15+

Detecting if SwiftUI is running in a Preview in Xcode

Fixing CocoaPods "Unknown ISA PBXFileSystemSynchronizedRootGroup" Error

Ways to Shoot Yourself in the Foot with Method Swizzling