From this goji issue 13 right command:
go get goji.io
This page http://goji.io/has a meta directive go-import:
<meta name="go-import" content="goji.io git https://github.com/goji/goji">
Thus, go does not take into account goji.io/internal(see, for example router.go), because it is trying to import the internal package of the “third party it.”
This problem illustrates the wrong internal import:
You are not allowed to import the internal package (or its subpackages) of a third-party repo.