When we were working on Glide, a package manager that manages your vendor/ directory, we needed to work with varying version control systems. While trying to use the golang.org/x/tools/go/vcs package we found it to be too tightly coupled to the go get command. When we wanted to deviate from it’s features things got difficult.
Today we have the github.com/Masterminds/vcs package that provides a common interface to varying version control systems. I’ve written up a quick intro if anyone is interested.