Must use symlink for hidden docker socket otherwise "invalid cross-device link"

daemon/daemon.go

@@ -35,7 +35,7 @@ func StartDaemon(d Daemon) error {
 	if !d.Disabled {
 		startDaemon(d)
 	} else if !d.NotHiddenSocket {
-		if err := os.Link(HiddenDockerSocketPath, StdDockerSocketPath); err != nil {
+		if err := os.Symlink(HiddenDockerSocketPath, StdDockerSocketPath); err != nil {
 			return errors.Wrap(err, "failed to link hidden docker socket to common one")
 		}
 	}