Solving the google_sign_in Build Failure in Flutter: A Guide to GTMAppAuth Issues

Encountering `google_sign_in` build failures in Flutter due to GTMAppAuth issues? Discover how to resolve the Undefined symbol error step-by-step.
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Introduction

When developing an iOS app using Flutter, you might encounter build failures after integrating the google_sign_in package. One common issue that developers face relates to GTMAppAuth, particularly the error involving Undefined symbol _GTMBridgeAssertValidSelector. This error can halt your development process, but fear not! Let's delve into the issue and understand how to resolve it effectively.

What Causes This Build Failure?

The Undefined symbol error signifies a linking problem during the build process. It often arises when a dependency required by a package isn’t correctly integrated into the project. Specifically, in your case, the culprit appears to be the GTMSessionFetcher version being used alongside the google_sign_in dependency.

Solution Steps to Fix the Build Failure

Follow these detailed steps to resolve the build issue associated with the google_sign_in package in your Flutter project.

Step 1: Locate the Podfile

Navigate to your Flutter project directory.

Locate the ios folder and find the Podfile. The Podfile controls the CocoaPods dependencies for your Flutter application.

Step 2: Modify the Podfile

To fix the issue, you need to explicitly tell CocoaPods to use a compatible version of GTMSessionFetcher. Here’s how to do that:

Open the Podfile in a text editor.

Update the target block in your Podfile to include a specific dependency version. Add the line for GTMSessionFetcher as shown below:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Run Pod Install

After saving the changes in the Podfile, you need to install the updated dependencies. Open your terminal and run the following command:

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Clean and Build Your Project

Once the pods are installed, go back to your Flutter project root. It’s recommended to clean the build and then rebuild your Flutter project to ensure everything is working correctly:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By following these steps, you should be able to resolve the build failure caused by google_sign_in and GTMAppAuth integration issues. Downgrading GTMSessionFetcher to the compatible version (1.5.0 in this case) enables a successful build without the Undefined symbol errors. Keep this guide handy as you continue to develop your Flutter app, and happy coding!