Understanding the Error: A Deep Dive into iOS Development and Xcode 7

Introduction

As a developer working with Xcode 7, it’s not uncommon to encounter unexpected errors when building and running iOS projects. One such error that has been reported by several users is related to the libcommonCrypto.dylib file in the iPhoneSimulator9.1.sdk directory. In this article, we’ll delve into the technical details of this issue, explore possible solutions, and provide a step-by-step guide on how to resolve it.

Understanding the Error

The error message indicates that the libcommonCrypto.dylib file is universal (2 slices) but does not contain an x86_64 slice. This means that the library is built with multiple architectures, including x86_64, but the x86_64-specific version of the library is missing.

To understand this issue better, let’s first look at what libcommonCrypto.dylib is and its role in iOS development.

What is libcommonCrypto.dylib?

libcommonCrypto.dylib is a dynamic link library that provides common cryptographic functions for iOS applications. It’s a crucial component of the iOS security framework and is used extensively throughout Apple’s own apps, including Safari and Mail.

The library contains various cryptographic algorithms, such as AES, DES, and SHA-1, which are used to encrypt and decrypt data, authenticate messages, and verify digital signatures.

Xcode 7 and iPhoneSimulator9.1.sdk

In Xcode 7, the iPhoneSimulator9.1.sdk directory is updated to include a newer version of the iOS SDK. This update introduces changes in the way libraries are compiled and packaged for iOS development.

The libcommonCrypto.dylib file is one such library that has been updated with multiple architectures (including x86_64) but may not have been fully optimized for each architecture.

Possible Causes

There are a few possible reasons why you might encounter this error:

• Incompatible library versions: If the version of libcommonCrypto.dylib used in your project is incompatible with the newer SDK, it can cause issues.
• Missing x86_64 slice: As mentioned earlier, the missing x86_64-specific slice could be a common issue due to the way libraries are compiled and packaged for iOS development.
• Security framework issues: The libcommonCrypto.dylib file is part of the security framework, which can sometimes cause conflicts or errors.

Solution: Removing and Re-Adding Libraries

One possible solution to this error is to remove libCommonCrypto.dylib and libz.dylib from your project’s linker flags and then re-add the security framework (specifically, security.framework and javascript.framework) to your target.

Here are the steps:

1. Open your project in Xcode.
2. Go to the project navigator.
3. Select the target that you want to update.
4. In the “General” tab, go to the “Linking” section.
5. Remove libCommonCrypto.dylib and libz.dylib from the list of libraries.

6. Go to the “Build Settings” tab.
7. Search for “Framework” in the search bar at the top-right corner of the screen.
8. Find security.framework and select it.
9. Make sure that both “Headers For Included In Interface Builder” and “Compile With Embedded Frameworks” are set to yes.

10. Repeat the above steps for javascript.framework.
11. Go back to the “General” tab.
12. Select the target that you updated earlier.
13. In the “Linking” section, go to the “Header Search Paths” and add the path to the security.framework and javascript.framework.

After making these changes, rebuild your project and see if the error persists. If it does, you can try to re-add the missing x86_64 slice or consult with Apple’s documentation for more information on how to resolve this issue.

Additional Tips

• When working with frameworks and libraries in Xcode, make sure that you have the latest version installed.
• Regularly update your project’s build settings and file paths to ensure compatibility with newer versions of the SDK.
• If you’re experiencing issues with the libcommonCrypto.dylib file, try re-compiling it manually or using a different compiler.

Conclusion

In this article, we’ve explored the technical details behind the libcommonCrypto.dylib error in Xcode 7 and provided a step-by-step guide on how to resolve it. By removing incompatible libraries, updating framework settings, and rebuilding your project, you should be able to successfully compile and run your iOS application without encountering this error.

If you have any further questions or need additional assistance, feel free to ask!

Last modified on 2023-11-24