use github mirror for golang.org packages when getting golang.org http meta failed

cmd/dep/init.go

@@ -95,6 +95,7 @@ func (cmd *initCommand) Run(ctx *dep.Ctx, args []string) error {
 	if err != nil {
 		return errors.Wrap(err, "init failed: unable to create a source manager")
 	}
+
 	sm.UseDefaultSignalHandling()
 	defer sm.Release()
 

gps/deduce.go

@@ -26,6 +26,7 @@ var (
 	hgSchemes      = []string{"https", "ssh", "http"}
 	svnSchemes     = []string{"https", "http", "svn", "svn+ssh"}
 	gopkginSchemes = []string{"https", "http"}
+	stdlibPrefix   = "golang.org/x"
 )
 
 const gopkgUnstableSuffix = "-unstable"
@@ -74,6 +75,7 @@ var (
 	jazzRegex         = regexp.MustCompile(`^(?P<root>hub\.jazz\.net(/git/[a-z0-9]+/[A-Za-z0-9_.\-]+))((?:/[A-Za-z0-9_.\-]+)*)$`)
 	apacheRegex       = regexp.MustCompile(`^(?P<root>git\.apache\.org(/[a-z0-9_.\-]+\.git))((?:/[A-Za-z0-9_.\-]+)*)$`)
 	vcsExtensionRegex = regexp.MustCompile(`^(?P<root>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?/[A-Za-z0-9_.\-/~]*?\.(?P<vcs>bzr|git|hg|svn))((?:/[A-Za-z0-9_.\-]+)*)$`)
+	stdlibRegex       = regexp.MustCompile(`^(?P<root>golang\.org/x(/[A-Za-z0-9_.\-]+))((?:/[A-Za-z0-9_.\-]+)*)$`)
 )
 
 // Other helper regexes
@@ -467,6 +469,38 @@ func (m apacheDeducer) deduceSource(path string, u *url.URL) (maybeSources, erro
 	return mb, nil
 }
 
+type stdlibDeducer struct {
+	regexp *regexp.Regexp
+}
+
+func (m stdlibDeducer) deduceRoot(path string) (string, error) {
+	v := m.regexp.FindStringSubmatch(path)
+	if v == nil {
+		return "", fmt.Errorf("%s is not a valid path for a source on golang.org", path)
+	}
+	return stdlibPrefix + v[2], nil
+}
+
+func (m stdlibDeducer) deduceSource(path string, u *url.URL) (maybeSources, error) {
+	v := m.regexp.FindStringSubmatch(path)
+	if v == nil {
+		return nil, fmt.Errorf("%s is not a valid path for a source on hub.jazz.net", path)
+	}
+
+	u.Host = "github.com"
+	u.Path = "/golang" + v[2]
+
+	switch u.Scheme {
+	case "":
+		u.Scheme = "https"
+		fallthrough
+	case "https":
+		return maybeSources{maybeGitSource{url: u}}, nil
+	default:
+		return nil, fmt.Errorf("golang.org use https, %s is not allowed", u.String())
+	}
+}
+
 type vcsExtensionDeducer struct {
 	regexp *regexp.Regexp
 }

gps/source_manager.go

@@ -552,6 +552,13 @@ func (sm *SourceMgr) DeduceProjectRoot(ip string) (ProjectRoot, error) {
 	}
 
 	pd, err := sm.deduceCoord.deduceRootPath(context.TODO(), ip)
+
+	// as we can not deduce root path from golang.org,
+	// try github mirror and add golang.org/x rules to Trie tree
+	if err != nil && strings.HasPrefix(ip, stdlibPrefix) {
+		sm.deduceCoord.deducext.Insert(stdlibPrefix, stdlibDeducer{regexp: stdlibRegex})
+		pd, err = sm.deduceCoord.deduceKnownPaths(ip)
+	}
 	return ProjectRoot(pd.root), err
 }