From 8f6b25e0acf85baea153276ff2bb55aa6a11b2dd Mon Sep 17 00:00:00 2001
From: Sauyon Lee <sauyon@github.com>
Date: Tue, 25 Aug 2020 03:51:13 -0700
Subject: [PATCH] autobuilder: Use -mod=mod for vendor directories wihtout
 modules.txt

---
 extractor/cli/go-autobuilder/go-autobuilder.go | 3 +++
 extractor/util/util.go                         | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/extractor/cli/go-autobuilder/go-autobuilder.go b/extractor/cli/go-autobuilder/go-autobuilder.go
index 75503aaeeec..99f9af145c9 100644
--- a/extractor/cli/go-autobuilder/go-autobuilder.go
+++ b/extractor/cli/go-autobuilder/go-autobuilder.go
@@ -244,7 +244,10 @@ func main() {
 	// skip the dependency installation step and run the extractor with `-mod=vendor`
 	if util.FileExists("vendor/modules.txt") {
 		modMode = ModVendor
+	} else if util.DirExists("vendor") {
+		modMode = modModIfSupported()
 	}
+
 	if modMode == ModVendor {
 		// fix go vendor issues with go versions >= 1.14 when no go version is specified in the go.mod
 		// if this is the case, and dependencies were vendored with an old go version (and therefore
diff --git a/extractor/util/util.go b/extractor/util/util.go
index c8eeb33f484..a592224672c 100644
--- a/extractor/util/util.go
+++ b/extractor/util/util.go
@@ -91,3 +91,12 @@ func FileExists(filename string) bool {
 	}
 	return err == nil && !info.IsDir()
 }
+
+// DirExists tests whether `filename` exists and is a directory.
+func DirExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if err != nil && !os.IsNotExist(err) {
+		log.Printf("Unable to stat %s: %s\n", filename, err.Error())
+	}
+	return err == nil && info.IsDir()
+}