This snippet shows how to leverage decoupled, multi-project builds in Gradle.

build.gradle

def sibling = { group, name, version ->
    try {
        def dep = project(":$name")
        if (dep.version == version) {
            logger.info("Using locally checked out $group:$name")
            return dep
        }
        logger.debug("Version mismatch for $group:$name, expected $version but had ${dep.version}")
    } catch (UnknownProjectException e) {
        logger.debug("Project $group:$name was missing")
    }
    logger.info("Using external dependency $group:$name")
    return "$group:$name:$version"
}

dependencies {
    compile sibling(typesGroup, 'my-types', myTypesVersion)
    
    // Amd with a dependency customizing closure...NOTE the comma after sibling(...)
    compile sibling(libGroup, 'my-lib', myLibVersion), {
        exclude group:'log4j', module:'log4j'
    }
}

settings.gradle

['my-lib','my-types'].each { sibling ->
    if (file("../$sibling").exists()) {
        includeFlat sibling
    }
}