What has been an issue for me, though, is working with private repositories outside GitHub (and I have to clarify that, because working with private repositories on GitHub is different, because Go has hardcoded settings specifically to make GitHub work).
I had hopes for the GOAUTH environment variable, but either (1) I'm more dumb and blind than I thought I already was, or (2) there's still no way to force Go to fetch a module using SSH without trying an HTTPS request first. And no, `GOPRIVATE="mymodule"` and `GOPROXY="direct"` don't do the trick, not even combined with Git's `insteadOf`.