在使用 Capistrano 不是项目时报错：

#<Thread:0x00000000114e4b28@/home/xxx/.rbenv/versions/2.5.0/lib/ruby/gems/2.5.0/gems/sshkit-1.23.2/lib/sshkit/runners/parallel.rb:10 run> terminated with exception (report_on_exception is true):
SSHKit::Runner::ExecuteError: Exception while executing as user@ip: agent could not sign data with requested identity

不知道怎么解决，希望有大佬能帮忙看看