Example conditions :
module mycode-1.4 has a transitive dependency on module hibernate-3.0.5
mycode is in my local maven repository but not the global maven repo
hibernate's poms exist in my local maven repository but the jars do not
hibernate jars are in the global maven repo

then:

dependencies{
addMavenRepo()
addMavenStyleRepo('myrepo', 'http://myrepo.com/maven-repo')
compile "me:mycode:1.4"
}

will not be able to resolve the runtime dependency on hibernate because it will find the poms in the local maven repository but not the jars, without ever checking the global maven repository.