Builds at commandline but fails to build as gae app - google-app-engine

Question

No issues building at commandline:
Darians-MacBook-Pro:gdriveweb darianhickman$ go build helloworld/hello.go
Darians-MacBook-Pro:gdriveweb darianhickman$
Error at locahost:8080/
The Go application could not be built.
(Executed command: /Users/darianhickman/go_appengine/goroot/bin/go-app-builder -app_base /Users/darianhickman/gowork/src/bitbucket.org/darian_hickman/gdriveweb/helloworld -arch 6 -dynamic -goroot /Users/darianhickman/go_appengine/goroot -nobuild_files ^^$ -unsafe -gopath /Users/darianhickman/gowork -binary_name _go_app -extra_imports appengine_internal/init -work_dir /var/folders/fk/wknp5jzn53gbgbml0yn695_m0000gn/T/tmpsHFP6tappengine-go-bin -gcflags -I,/Users/darianhickman/go_appengine/goroot/pkg/darwin_amd64_appengine -ldflags -L,/Users/darianhickman/go_appengine/goroot/pkg/darwin_amd64_appengine hello.go)
/Users/darianhickman/gowork/src/golang.org/x/net/context/ctxhttp/ctxhttp.go:35: req.Cancel undefined (type *http.Request has no field or method Cancel)
2016/05/24 19:39:17 go-app-builder: build timing: 6×6g (469ms total), 0×6l (0 total)
2016/05/24 19:39:17 go-app-builder: failed running 6g: exit status 1
When I research the error
*http.Request has no field or method Cancel
it leads to a bunch of nonapplicable posts about updating to >Go1.5.
Source:
package hello
import (
"encoding/json"
"fmt"
"golang.org/x/net/context"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
"google.golang.org/api/drive/v3"
_ "google.golang.org/appengine/urlfetch"
"io/ioutil"
"log"
"net/http"
"net/url"
"os"
"os/user"
"path/filepath"
)
const (
assetfolder = "0B-zdryEj60U_MXVkajFweXBQWHM"
)
var (
dir *drive.FileList
)
func init() {
http.HandleFunc("/", handler)
ctx := context.Background()
b, err := ioutil.ReadFile("client_secret.json")
if err != nil {
log.Fatalf("Unable to read client secret file: %v", err)
}
// If modifying these scopes, delete your previously saved credentials
// at ~/.credentials/drive-go-quickstart.json
config, err := google.ConfigFromJSON(b, drive.DriveMetadataReadonlyScope)
if err != nil {
log.Fatalf("Unable to parse client secret file to config: %v", err)
}
client := getClient(ctx, config)
srv, err := drive.New(client)
if err != nil {
log.Fatalf("Unable to retrieve drive Client %v", err)
}
dir, err = srv.Files.List().PageSize(10).
Fields("nextPageToken, files(id, name)").Do()
if err != nil {
log.Fatalf("Unable to retrieve files.", err)
}
}
func handler(w http.ResponseWriter, r *http.Request) {
//fmt.Fprint(w, r.RequestURI)
fmt.Fprint(w, "Files:")
if len(dir.Files) > 0 {
for _, i := range dir.Files {
fmt.Fprint(w, "%s (%s)\n", i.Name, i.Id)
}
} else {
fmt.Fprint(w, "No files found.")
}
}
// getClient uses a Context and Config to retrieve a Token
// then generate a Client. It returns the generated Client.
func getClient(ctx context.Context, config *oauth2.Config) *http.Client {
cacheFile, err := tokenCacheFile()
if err != nil {
log.Fatalf("Unable to get path to cached credential file. %v", err)
}
tok, err := tokenFromFile(cacheFile)
if err != nil {
tok = getTokenFromWeb(config)
saveToken(cacheFile, tok)
}
return config.Client(ctx, tok)
}
// getTokenFromWeb uses Config to request a Token.
// It returns the retrieved Token.
func getTokenFromWeb(config *oauth2.Config) *oauth2.Token {
authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
fmt.Printf("Go to the following link in your browser then type the "+
"authorization code: \n%v\n", authURL)
var code string
if _, err := fmt.Scan(&code); err != nil {
log.Fatalf("Unable to read authorization code %v", err)
}
tok, err := config.Exchange(oauth2.NoContext, code)
if err != nil {
log.Fatalf("Unable to retrieve token from web %v", err)
}
return tok
}
// tokenCacheFile generates credential file path/filename.
// It returns the generated credential path/filename.
func tokenCacheFile() (string, error) {
usr, err := user.Current()
if err != nil {
return "", err
}
tokenCacheDir := filepath.Join(usr.HomeDir, ".credentials")
os.MkdirAll(tokenCacheDir, 0700)
return filepath.Join(tokenCacheDir,
url.QueryEscape("drive-go-quickstart.json")), err
}
// tokenFromFile retrieves a Token from a given file path.
// It returns the retrieved Token and any read error encountered.
func tokenFromFile(file string) (*oauth2.Token, error) {
f, err := os.Open(file)
if err != nil {
return nil, err
}
t := &oauth2.Token{}
err = json.NewDecoder(f).Decode(t)
defer f.Close()
return t, err
}
// saveToken uses a file path to create a file and store the
// token in it.
func saveToken(file string, token *oauth2.Token) {
fmt.Printf("Saving credential file to: %s\n", file)
f, err := os.Create(file)
if err != nil {
log.Fatalf("Unable to cache oauth token: %v", err)
}
defer f.Close()
json.NewEncoder(f).Encode(token)
}
func main() {
ctx := context.Background()
b, err := ioutil.ReadFile("client_secret.json")
if err != nil {
log.Fatalf("Unable to read client secret file: %v", err)
}
// If modifying these scopes, delete your previously saved credentials
// at ~/.credentials/drive-go-quickstart.json
config, err := google.ConfigFromJSON(b, drive.DriveMetadataReadonlyScope)
if err != nil {
log.Fatalf("Unable to parse client secret file to config: %v", err)
}
client := getClient(ctx, config)
srv, err := drive.New(client)
if err != nil {
log.Fatalf("Unable to retrieve drive Client %v", err)
}
r, err := srv.Files.List().PageSize(10).
Fields("nextPageToken, files(id, name)").Do()
if err != nil {
log.Fatalf("Unable to retrieve files.", err)
}
fmt.Println("Files:")
if len(r.Files) > 0 {
for _, i := range r.Files {
fmt.Printf("%s (%s)\n", i.Name, i.Id)
}
} else {
fmt.Print("No files found.")
}
}

Answer 1

I got past this issue by redownloading and reinstalling Go App Engine SDK . My best guess why that worked is that an old version of go was somehow getting included.