How to locate information to resolve "Could not determine the dependencies of task ..." errors

I’m a self-taught programmer and have just built an Android app that I am hoping to test and have up to now allowed Android Studio do the heavy lifting with regards to Gradle. I am trying to start testing, following the information provided on and and am running into problems such as that indicated in the following error message:

Caused by: org.gradle.api.internal.artifacts.ivyservice.DefaultLenientConfiguration$ArtifactResolveException: Could not resolve all task dependencies for configuration ‘:app:debugAndroidTestRuntimeClasspath’.

I have added all the dependencies to my app’s build.gradle file as shown in the Developer pages and believe that this message has found that I have not. I don’t even know where to begin to identify what debugAndroidTestRuntimeClasspath is referring to so that I can add its required dependencies (I used GREP to look for classpaths in my Android project and don’t know which files, if any, it has found fault with).

My question is: where in the Gradle documentation is information provided that would help me resolve this specific problem?

There must be something here that explains what Gradle is looking at to specify that it can’t find a classpath because people use Gradle written by hand and they would need this information. NOTE: I am reading through the Gradle documentation now, but would like to resolve these issues to be able to test my app prior to releasing to testers.

Thanks in advance, Jeff