deployer: Won't git clone from private repo but forwardAgent() connection is done.

I use: server(‘ssss’, ‘111.111.111.111’) ->user(‘uuuu’) ->forwardAgent();

Connect is done, and all tasks before deploy:update_code is done too. On deploy:update_code raise exception:

  [RuntimeException]                          
  Permission denied (publickey).              
  fatal: The remote end hung up unexpectedly.

But if I manualy connect by ssh uuuu@111.111.111.111 and exec git clone -b master --depth 1 --recursive -q git@github.com:oooo/rrrr.git rrrr - it working good.

I configured local(ubuntu) and server(debian7) in accordance with https://github.com/oanhnn/deployer-example/blob/master/docs/enable-feature-ssh-forward-agent.md (but in my server no sshd service, it’s name ssh). This has no effect.