如何使用gopkg安装ginkgo和gomega？

I am trying to install ginkgo and gomega using the gopkg. It is throwing the following error:

src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:24:2: use of internal package not allowed
src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:25:2: use of internal package not allowed
src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:26:2: use of internal package not allowed
src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:27:2: use of internal package not allowed
src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:28:2: use of internal package not allowed
src/gopkg.in/onsi/ginkgo.v1/ginkgo_dsl.go:29:2: use of internal package not allowed

src/gopkg.in/onsi/gomega.v1/gomega_dsl.go:21:2: use of internal package not allowed
src/gopkg.in/onsi/gomega.v1/gomega_dsl.go:22:2: use of internal package not allowed
src/gopkg.in/onsi/gomega.v1/gomega_dsl.go:23:2: use of internal package not allowed

To my understanding, this is not a fatal error. I was able to download both ginkgo and gomega using gopkg even though I got the same warning messages. A brief look at the source code shows that gomega_dsl.go and ginkgo_dsl.go import code from an internal subdirectory. I do not see why that should be a problem, though. Getting the packages worked despite these warnings.