go-swag.patch

diff --git a/packages.go b/packages.go
index 69a1b05..466db86 100644
--- a/packages.go
+++ b/packages.go
@@ -93,7 +93,7 @@ func (pkgDefs *PackagesDefinitions) RangeFiles(handle func(info *AstFileInfo) er
 	for _, info := range pkgDefs.files {
 		// ignore package path prefix with 'vendor' or $GOROOT,
 		// because the router info of api will not be included these files.
-		if strings.HasPrefix(info.PackagePath, "vendor") || strings.HasPrefix(info.Path, runtime.GOROOT()) {
+		if strings.HasPrefix(info.PackagePath, "vendor") || (runtime.GOROOT() != "" && strings.HasPrefix(info.Path, runtime.GOROOT())) {
 			continue
 		}
 		sortedFiles = append(sortedFiles, info)