check for a couple errors

builder/amazon/chroot/communicator.go

@@ -69,7 +69,10 @@ func (c *Communicator) Upload(dst string, r io.Reader, fi *os.FileInfo) error {
 		return fmt.Errorf("Error preparing shell script: %s", err)
 	}
 	defer os.Remove(tf.Name())
-	io.Copy(tf, r)
+
+	if _, err := io.Copy(tf, r); err != nil {
+		return err
+	}
 
 	cpCmd, err := c.CmdWrapper(fmt.Sprintf("cp %s %s", tf.Name(), dst))
 	if err != nil {

builder/amazon/common/step_run_source_instance.go

@@ -342,7 +342,10 @@ func (s *StepRunSourceInstance) Cleanup(state multistep.StateBag) {
 			Target:  "cancelled",
 		}
 
-		WaitForState(&stateChange)
+		_, err := WaitForState(&stateChange)
+		if err != nil {
+			ui.Error(err.Error())
+		}
 
 	}
 
@@ -359,6 +362,9 @@ func (s *StepRunSourceInstance) Cleanup(state multistep.StateBag) {
 			Target:  "terminated",
 		}
 
-		WaitForState(&stateChange)
+		_, err := WaitForState(&stateChange)
+		if err != nil {
+			ui.Error(err.Error())
+		}
 	}
 }

communicator/ssh/communicator.go

@@ -250,7 +250,7 @@ func (c *comm) newSession() (session *ssh.Session, err error) {
 
 func (c *comm) reconnect() (err error) {
 	if c.conn != nil {
-		c.conn.Close()
+		return c.conn.Close()
 	}
 
 	// Set the conn and client to nil since we'll recreate it