Fixing DEVELOPER_ERROR in React Native SSO with Google in Android (without Firebase)

Everyone is telling you that it’s a SHA1 mismatch problem, but there’s also another possibility like a package name mismatch…

If you followed a random tutorial while preparing your React Native app to run in Android, there’s a chance that you have created product flavors in your build.gradle file. This unfortunately ends up by altering the package name of your app with applicationIdSuffixes, which ends up with a silent failure with a package name mismatch.

When using this setup, your app’s package name is prepared as “com.yourcompany.yourappname.production” instead of com.yourcompany.yourappname”, and in case you input the latter one into the Google Cloud in combination with the SHA1 value you grabbed from your console, the integration simply fails.

The solution is either to set the applicationIdSuffix to an empty string, or to use the correct package name including the suffix, in the Google Cloud. I went with the first solution.

You are unable to easily tell the problem because of the worst error message in the world coming from Google: DEVELOPER_ERROR. Yeah, if they could only mind to put a “package name mismatch” information as an addition, I could have easily saved half of my day.

Anyway, I hope this piece of information helps you to save your time.