fix region stuff

builder/amazon/common/access_config.go

@@ -54,11 +54,11 @@ func (c *AccessConfig) Session() (*session.Session, error) {
 	// retries are exponentially backed off.
 	config = config.WithMaxRetries(8)
 
-	region, err := c.region()
+	region, _ := c.region()
-	if err != nil {
+	// if err != nil {
-		return nil, fmt.Errorf("Could not get region, "+
+	// 	return nil, fmt.Errorf("Could not get region, "+
-			"probably because it's not set or we're not running on AWS. %s", err)
+	// 		"probably because it's not set or we're not running on AWS. %s", err)
-	}
+	// }
 	config = config.WithRegion(region)
 
 	if c.CustomEndpointEc2 != "" {

builder/amazon/common/regions.go

@@ -34,6 +34,9 @@ func (c *AccessConfig) ValidateRegion(regions ...string) error {
 
 	var invalidRegions []string
 	for _, region := range regions {
+		if region == "" {
+			continue
+		}
 		found := false
 		for _, validRegion := range validRegions {
 			if region == validRegion {