given I have a private (corporate self-hosted) git repository which listens on on another but the default http-port. (For example 6655)
The full repository-url to my
Another solution is to change your .gitconfig to work with ports.
[url "git@internal-git.corporate-domain.com:6655"]
  insteadOf = git://internal-git.corporate-domain.com
Like a previous comment said you probably want to clone the Git repository into your $GOPATH (%GOPATH% for Windows) directory.
Per your example the clone command would look like:
git clone internal-git.corporate-domain.com:6655/~myuser/golang-lib.git $GOPATH/corporate-domain.com/golang-lib
And your import in Go source files would look like:
import "corporate-domain.com/golang-lib"