wgengine/router: include command output if `ip rule list` fails.
@@ -391,7 +391,7 @@ func (r *linuxRouter) addBypassRule() error {
func (r *linuxRouter) delBypassRule() error {
out, err := exec.Command("ip", "rule", "list", "priority", "10000").CombinedOutput()
if err != nil {
- return err
+ return fmt.Errorf("listing ip rules: %v\n%s", err, out)
}
if len(out) == 0 {
// No rule exists.
