fix symlink checks to use OS file mode, not git file mode

cmd/gomodproxy/main.go

@@ -132,14 +132,6 @@ func main() {
 	}
 	options = append(options, api.Log(logger))
 
-	for _, path := range vcsPaths {
-		kv := strings.SplitN(path, ":", 2)
-		if len(kv) != 2 {
-			log.Fatal("bad VCS syntax:", path)
-		}
-		options = append(options, api.CustomVCS(kv[0], kv[1]))
-	}
-
 	for _, path := range gitPaths {
 		kv := strings.SplitN(path, ":", 2)
 		if len(kv) != 2 {
@@ -148,6 +140,14 @@ func main() {
 		options = append(options, api.Git(kv[0], kv[1]))
 	}
 
+	for _, path := range vcsPaths {
+		kv := strings.SplitN(path, ":", 2)
+		if len(kv) != 2 {
+			log.Fatal("bad VCS syntax:", path)
+		}
+		options = append(options, api.CustomVCS(kv[0], kv[1]))
+	}
+
 	options = append(options,
 		api.VCSWorkers(*workers),
 		api.GitDir(*gitdir),

pkg/vcs/git.go

@@ -163,7 +163,11 @@ func (g *gitVCS) Zip(ctx context.Context, version Version) (io.ReadCloser, error
 		if submodule(f.Name) {
 			continue
 		}
-		if !f.Mode.IsRegular() {
+		mode, err := f.Mode.ToOSFileMode()
+		if err != nil {
+			return nil, err
+		}
+		if !mode.IsRegular() {
 			continue
 		}
 		name := f.Name