Clone a repository from GitHub Enterprise with go-git

I'm trying to use go-git to clone a repository from GitHub Enterprise. To do that, I'm using the HTTPS protocol with an access token with appropriate permissions for my repos (verified on the command line). go-git fails when making the git-upload-pack RPC call because the server responds with a 400:

$ go run main.go
unexpected client error: unexpected requesting "https://github.mycompany.net/my-org/myrepo.git/info/refs?service=git-upload-pack" status code: 400

The request it makes is equivalent to this:

GET /my-org/myrepo.git/info/refs?service=git-upload-pack HTTP/1.1
Host: github.mycompany.net
User-Agent: git/1.0
Accept: */*
Authorization: Bearer atokenthatisdefinitelyvalid

Without the token in the request header, I get the expected 401 (Anonymous access denied) response from the repository. With the token, it responds with a 400.

I have found the same to be true for public repositories on non-Enterprise GitHub; with the difference that it (expectedly) works without an Authorization header since none is necessary. If I include a valid token, GitHub just like its Enterprise version responds with a 400.

Below is a minimal example. Is there a way to use go-git with GitHub Enterprise that requires authentication? Ideally using an auth token?

package main

import (
    "fmt"
    "io/ioutil"

    git "gopkg.in/src-d/go-git.v4"
    "gopkg.in/src-d/go-git.v4/plumbing"
    "gopkg.in/src-d/go-git.v4/plumbing/transport/http"
)

const (
    repoURL           = "https://github.mycompany.net/my-org/myrepo.git"
    githubAccessToken = "atokenthatisdefinitelyvalid"
)

func main() {
    dir, _ := ioutil.TempDir("", "temp_dir")

    options := &git.CloneOptions{
        Auth:          &http.TokenAuth{Token: githubAccessToken},
        URL:           repoURL,
        Depth:         500,
        ReferenceName: plumbing.ReferenceName("refs/heads/master"),
        SingleBranch:  true,
        Tags:          git.NoTags,
    }

    _, err := git.PlainClone(dir, false, options)
    fmt.Println(err)
}

Turns out that Github uses the token as a password for your user, so it requires a basic authentication rather than a token in the header:

options := &git.CloneOptions{
    Auth:          &http.BasicAuth{Username: "myusername", Token: "mytoken"},
    URL:           repoURL,
    Depth:         500,
    ReferenceName: plumbing.ReferenceName("refs/heads/master"),
    SingleBranch:  true,
    Tags:          git.NoTags,
}