gosimple/oauth2 and Google OAuth2

I'm using the gosimple/oauth2 package to handle OAuth2 logins for users. I have zero problems with the GitHub example code, which works perfectly and returns what I want.

I do, however, have issues getting it to work with Google. I've defined my scope correctly (as far as I can see), and I'm getting a token response, but once I enter it in, the application panics at ~line 68.

package main

import (
	"bitbucket.org/gosimple/oauth2"
	"flag"
	"fmt"
	"io"
	"log"
	"os"
)

var (
	// Register new app at https://github.com/settings/applications and provide
	// clientId (-id), clientSecret (-secret) and redirectURL (-redirect)
	// as imput arguments.
	clientId     = flag.String("id", "", "Client ID")
	clientSecret = flag.String("secret", "", "Client Secret")
	redirectURL  = flag.String("redirect", "http://httpbin.org/get", "Redirect URL")
	scopeURL     = flag.String("scope", "https://www.googleapis.com/auth/userinfo.profile", "Scope URL")

	authURL    = "https://accounts.google.com/o/oauth2/auth"
	tokenURL   = "https://www.googleapis.com/oauth2/v1/userinfo"
	apiBaseURL = "https://www.googleapis.com/"
)

const startInfo = `
Register new app at https://github.com/settings/applications and provide
-id, -secret and -redirect as input arguments.
`

func main() {
	flag.Parse()

	if *clientId == "" || *clientSecret == "" {
		fmt.Println(startInfo)
		flag.Usage()
		os.Exit(2)
	}

	// Initialize service.
	service := oauth2.Service(
		*clientId, *clientSecret, authURL, tokenURL)
	service.RedirectURL = *redirectURL
	service.Scope = *scopeURL

	// Get authorization url.
	aUrl := service.GetAuthorizeURL("")
	fmt.Println("\n", aUrl)

	// Open authorization url in default system browser.
	//webbrowser.Open(url)

	fmt.Printf("\nVisit URL and provide code: ")
	code := ""
	// Read access code from cmd.
	fmt.Scanf("%s", &code)
	// Get access token.
	token, _ := service.GetAccessToken(code)
	fmt.Println()

	// Prepare resource request.
	google := oauth2.Request(apiBaseURL, token.AccessToken)
	google.AccessTokenInHeader = false
	google.AccessTokenInHeaderScheme = "token"
	//google.AccessTokenInURL = true

	// Make the request.
	apiEndPoint := "user"
	googleUserData, err := google.Get(apiEndPoint)
	if err != nil {
		log.Fatal("Get:", err)
	}
	defer googleUserData.Body.Close()

	fmt.Println("User info response:")
	// Write the response to standard output.
	io.Copy(os.Stdout, googleUserData.Body)

	fmt.Println()
}

And the panic:

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x2341]

This is the offending line:

google := oauth2.Request(apiBaseURL, token.AccessToken)

I'd appreciate help to get this working. Note that the code is just modified example code from the gosimple/oauth2 repo I'm trying to debug this stage before wrapping it with the controller methods in my application.

Full stack trace as below:

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x2341]

goroutine 1 [running]:
main.main()
        /Users/matt/Desktop/tests/google_demo.go:68 +0x341

goroutine 2 [syscall]:

goroutine 5 [runnable]:
net/http.(*persistConn).readLoop(0xc2000bd100)
        /usr/local/Cellar/go/1.1/src/pkg/net/http/transport.go:761 +0x64b
created by net/http.(*Transport).dialConn
        /usr/local/Cellar/go/1.1/src/pkg/net/http/transport.go:511 +0x574

goroutine 6 [select]:
net/http.(*persistConn).writeLoop(0xc2000bd100)
        /usr/local/Cellar/go/1.1/src/pkg/net/http/transport.go:774 +0x26f
created by net/http.(*Transport).dialConn
        /usr/local/Cellar/go/1.1/src/pkg/net/http/transport.go:512 +0x58b

... and forcing a panic on a token error:

panic: No access token found, response: [78 111 116 32 70 111 117 110 100]

This was due to a bug in the library's token handling, which I logged with the author and which was fixed within the day: https://bitbucket.org/gosimple/oauth2/commits/e8e925ffb2424645cceaa9534e0ed9a28e564a20