Metamask: MetaMask + Unity iOS build crashes on startup

Here is a step-by-step guide to help you identify and resolve the issue:

Understanding the Issue

The issue is that the Unity iOS build process fails when attempting to load MetaMask, which requires a specific setup. The failure occurs at startup due to an invalid script.

Debugging Steps

• Verify Bitcode Settings

  : Make sure that the “Bitcode – Disabled” setting in Unity settings is not enabled. This can prevent the compiler from generating the necessary metadata for an iOS build.

• Check the scriptable backend: Switch back to IL2CPP, which is recommended for iOS development. However, if you want to stay with IL2CPP, make sure that it is configured correctly and is not causing any issues.

• Verify Code Generation Settings: Check the “Code Generation – Faster Smaller Builds” setting in Unity settings. This may be improperly optimized for your project, which may cause it to fail when trying to load MetaMask.

Further Investigation

• Inspect Xcode Logs: Run the following command in Xcode to inspect the logs:

xcrun lldb 

`

You will see a detailed log of any errors that occur during the build process.

• Check for other errors: Review the Xcode logs to make sure there are no other errors or warnings related to MetaMask configuration or iOS builds.

Potential Solutions

• Disable Bitcode: Try turning off the “Bitcode – Disabled” setting in Unity settings until the issue is resolved.

• Try IL2CPP: Switch back to IL2CPP as recommended in the Unity documentation. If this resolves the issue, you may need to investigate why it is not working properly.

• Optimize Code Generation: Check the “Code Generation – Faster Smaller Builds” settings and optimize them if necessary.

• Reinstall MetaMask: Try reinstalling MetaMask using a different method (e.g. copy and paste the code into the Wallet app) and see if the issue persists.

Additional Tips

• Use Unity Hub

  : If you are having issues with your current setup, consider upgrading to Unity 2022.2 or later.

• Check for Updates: Make sure all dependencies are up to date to avoid compatibility issues.

• Report Issues: Share your issue on the Unity Community Forums so others can help resolve it.

Conclusion

The crash can be caused by a combination of factors and requires a careful review of Unity settings, Xcode logs, and code generation options to resolve. By following these steps, you should be able to identify and potentially resolve the MetaMask setup issue on iOS. Good luck!