使用退出代码运行capistrano部署时出现编写器错误：
composer exit status: 2
以下是错误的完整日志：
Invoke deploy:updated (first_time)
Invoke composer:install (first_time)
Execute composer:install
Invoke composer:run (first_time)
Execute composer:run
INFO[28cd8f39] Running /usr/bin/env composer install --no-dev --no-interaction --verbose --optimize-autoloader on mydomain.com
cap aborted!
SSHKit::Runner::ExecuteError: Exception while executing on host mydomain.com: composer exit status: 2
composer stdout: Nothing written
composer stderr: Nothing written
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/command.rb:97:in `exit_status='
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:148:in `block (5 levels) in _execute'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:551:in `call'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:551:in `do_request'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:561:in `channel_request'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:465:in `dispatch_incoming_packets'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:221:in `preprocess'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:205:in `process'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `block in loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:269:in `wait'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:170:in `block (3 levels) in _execute'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:514:in `call'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:545:in `channel_open_confirmation'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:465:in `dispatch_incoming_packets'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:221:in `preprocess'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:205:in `process'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `block in loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:172:in `block (2 levels) in _execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:186:in `with_ssh'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:131:in `block in _execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:128:in `tap'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:128:in `_execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/var/lib/gems/1.9.1/gems/capistrano-composer-0.0.4/lib/capistrano/tasks/composer.rake:27:in `block (4 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/abstract.rb:77:in `within'
/var/lib/gems/1.9.1/gems/capistrano-composer-0.0.4/lib/capistrano/tasks/composer.rake:26:in `block (3 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:54:in `run'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
SSHKit::Command::Failed: composer exit status: 2
composer stdout: Nothing written
composer stderr: Nothing written
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/command.rb:97:in `exit_status='
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:148:in `block (5 levels) in _execute'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:551:in `call'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:551:in `do_request'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:561:in `channel_request'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:465:in `dispatch_incoming_packets'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:221:in `preprocess'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:205:in `process'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `block in loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:269:in `wait'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:170:in `block (3 levels) in _execute'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:514:in `call'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/channel.rb:514:in `do_open_confirmation'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:545:in `channel_open_confirmation'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:465:in `dispatch_incoming_packets'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:221:in `preprocess'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:205:in `process'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `block in loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/net-ssh-2.9.1/lib/net/ssh/connection/session.rb:169:in `loop'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:172:in `block (2 levels) in _execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:186:in `with_ssh'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:131:in `block in _execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:128:in `tap'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:128:in `_execute'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:66:in `execute'
/var/lib/gems/1.9.1/gems/capistrano-composer-0.0.4/lib/capistrano/tasks/composer.rake:27:in `block (4 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/abstract.rb:77:in `within'
/var/lib/gems/1.9.1/gems/capistrano-composer-0.0.4/lib/capistrano/tasks/composer.rake:26:in `block (3 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:54:in `instance_exec'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/backends/netssh.rb:54:in `run'
/var/lib/gems/1.9.1/gems/sshkit-1.5.1/lib/sshkit/runners/parallel.rb:13:in `block (2 levels) in execute'
Tasks: TOP => composer:run
The deploy has failed with an error: #<SSHKit::Runner::ExecuteError: Exception while executing on host mydomain.com: composer exit status: 2
composer stdout: Nothing written
composer stderr: Nothing written
>
** Invoke deploy:failed (first_time)
** Execute deploy:failed
我使用的是capistrano版本3.2.0和最新版本的capistrano-composer。
可能是什么问题？
答案 0 :(得分：1)
（在评论或编辑中回答的问题。请参阅Question with no answers, but issue solved in the comments (or extended in chat)）
OP写道：不知何故，问题出在composer install命令中。我已经通过在composer安装之前运行composer update解决了这个问题，并且部署成功了。
这是运行composer的代码：在composer：install之前更新。
namespace :composer do
before 'install', 'change_dir'
desc 'Composer update'
task :change_dir do
on roles(:app) do
execute "cd #{release_path}/ && composer update"
end
end
end