Strange build failure when deploying GAE using gradle

You are now using the app-gradle-plugin version 2.0.0-rc1 as I can see from your console output, which was released 2 days ago. It has some changes, which the developers of the plugin documented.

As you can see in the Change Log of this release candidate from google, it mentions in the changes:

project and version are no longer pulled from the global gcloud state by default. project must be configured in build.gradle using the deploy.project property, users may use special keywords for project to specify that they would like to read it from appengine-web.xml (project = "APPENGINE_CONFIG") or from gcloud global state (project = "GCLOUD_CONFIG"). version is also configured the same way.

So you just have to specify in your gradle.build the following:

appengine {
    deploy {
        version = "GCLOUD_CONFIG"
        project = "GCLOUD_CONFIG"
    }
}

Update in 2.0.0-rc3 (Thanks to @wildcat12 for pointing it out) in the latest version 2.0.0-rc3, the project configuration property has changed.

Changed appengine.deploy.project -> appengine.deploy.projectId

Therefore, now your gradle.build configuration would look like that:

appengine {
    deploy {
        version = "GCLOUD_CONFIG"
        projectId = "GCLOUD_CONFIG"
    }
}