As an AI language model, I don't have enough context to understand the exact issue you're facing. However, based on the error message you've provided, it seems like there is an issue with the target name in your Xcode project.
Make sure that the target name "RunnerTests" exists in your Xcode project and that it is spelled correctly. It's possible that the target name has been changed or deleted, causing this issue.
You may also want to check if the target is properly included in the build settings of your project. Ensure that the appropriate build settings are configured for both the target and the project.
If you're still encountering issues, you may need to review the build process and perform some debugging to get more specific information on the error.