以 bundle stdout 形式出现的 Capistrano Deploy 错误：未写入 bundle stderr：未写入
Capistrano Deploy error in the form of bundle stdout: Nothing written bundle stderr: Nothing written
所以我最近设置了一个 Azure VM，并一直在尝试让我们的应用程序部署到 Azure。我遇到了一堆错误，但在我 运行 cap production deploy:check --trace
之后我真的被困在这里了
我们使用 Ansible 来设置服务器，nginx 在服务器上运行良好。现在我们只是想把该死的东西部署到机器上，但是我们遇到了一个奇怪的问题，它无法作为 deploy 用户执行，无论出于何种原因并说什么都没写。
如有任何帮助，我们将不胜感激。
cap aborted!
SSHKit::Runner::ExecuteError: Exception while executing as cow@goat.cloudapp.net: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/command.rb:97:in `exit_status='
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:153:in `block (5 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `do_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:562:in `channel_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:269:in `wait'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:175:in `block (3 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:546:in `channel_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:177:in `block (2 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:191:in `with_ssh'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:136:in `block in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `tap'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `_execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:35:in `block (5 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:85:in `with'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:26:in `block (4 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:77:in `within'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:25:in `block (3 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `run'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
SSHKit::Command::Failed: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/command.rb:97:in `exit_status='
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:153:in `block (5 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `do_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:562:in `channel_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:269:in `wait'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:175:in `block (3 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:546:in `channel_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:177:in `block (2 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:191:in `with_ssh'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:136:in `block in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `tap'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `_execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:35:in `block (5 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:85:in `with'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:26:in `block (4 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:77:in `within'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:25:in `block (3 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `run'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
Tasks: TOP => deploy:updated => bundler:install
The deploy has failed with an error: Exception while executing as cow@goat.cloudapp.net: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
** Invoke deploy:failed (first_time)
** Execute deploy:failed
根据 the source 退出状态 18 表示 Ruby 版本不匹配。通常，这表明您的 Gemfile 中有一个 ruby 行需要与您用于执行 Bundler 的版本不同的版本（在本例中为 2.2.0）。
令人惊讶的是，它说没有任何内容写入 stdout 或 stderr，因为 Bundler 通常会在这种情况下打印错误。可能还有其他问题导致错误输出被抑制。
所以我最近设置了一个 Azure VM，并一直在尝试让我们的应用程序部署到 Azure。我遇到了一堆错误，但在我 运行 cap production deploy:check --trace
我们使用 Ansible 来设置服务器，nginx 在服务器上运行良好。现在我们只是想把该死的东西部署到机器上，但是我们遇到了一个奇怪的问题，它无法作为 deploy 用户执行，无论出于何种原因并说什么都没写。
如有任何帮助，我们将不胜感激。
cap aborted!
SSHKit::Runner::ExecuteError: Exception while executing as cow@goat.cloudapp.net: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/command.rb:97:in `exit_status='
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:153:in `block (5 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `do_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:562:in `channel_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:269:in `wait'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:175:in `block (3 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:546:in `channel_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:177:in `block (2 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:191:in `with_ssh'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:136:in `block in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `tap'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `_execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:35:in `block (5 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:85:in `with'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:26:in `block (4 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:77:in `within'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:25:in `block (3 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `run'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
SSHKit::Command::Failed: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/command.rb:97:in `exit_status='
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:153:in `block (5 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:551:in `do_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:562:in `channel_request'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:269:in `wait'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:175:in `block (3 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `call'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:546:in `channel_open_confirmation'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:466:in `dispatch_incoming_packets'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:222:in `preprocess'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:206:in `process'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `block in loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/connection/session.rb:170:in `loop'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:177:in `block (2 levels) in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:191:in `with_ssh'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:136:in `block in _execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `tap'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:133:in `_execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:35:in `block (5 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:85:in `with'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:26:in `block (4 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/abstract.rb:77:in `within'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/capistrano-bundler-1.1.4/lib/capistrano/tasks/bundler.cap:25:in `block (3 levels) in <top (required)>'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/backends/netssh.rb:54:in `run'
/Users/macbook/.rbenv/versions/2.2.0/lib/ruby/gems/2.2.0/gems/sshkit-1.6.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
Tasks: TOP => deploy:updated => bundler:install
The deploy has failed with an error: Exception while executing as cow@goat.cloudapp.net: bundle exit status: 18
bundle stdout: Nothing written
bundle stderr: Nothing written
** Invoke deploy:failed (first_time)
** Execute deploy:failed
根据 the source 退出状态 18 表示 Ruby 版本不匹配。通常，这表明您的 Gemfile 中有一个 ruby 行需要与您用于执行 Bundler 的版本不同的版本（在本例中为 2.2.0）。
令人惊讶的是，它说没有任何内容写入 stdout 或 stderr，因为 Bundler 通常会在这种情况下打印错误。可能还有其他问题导致错误输出被抑制。