Capistrano error: undefined method `already_invoked' for <Rake::Task load:defaults => []>:Rake::Task

Question

I've spent way too much time debugging this, and I have no idea what's going on. "cap production deploy" worked fine this morning, and now it just throws an error. Google has not been of much help so far, surprisingly. Nothing has changed in the code base that I know of:

➜  sesac-mm-matching git:(deploy) cap production deploy --trace
    ** Invoke production (first_time)
    ** Execute production
    cap aborted!
    NoMethodError: undefined method `already_invoked' for <Rake::Task load:defaults => []>:Rake::Task
    /Users/***/.rvm/gems/ruby-2.3.0@global/gems/capistrano-3.6.0/lib/capistrano/dsl.rb:16:in `invoke'
    /Users/***/.rvm/gems/ruby-2.3.0@global/gems/capistrano-3.6.0/lib/capistrano/setup.rb:24:in `block (2 levels) in <top (required)>'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:240:in `block in execute'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:235:in `each'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:235:in `execute'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
    /Users/***/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/monitor.rb:214:in `mon_synchronize'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:172:in `invoke_with_call_chain'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/task.rb:165:in `invoke'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:150:in `invoke_task'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:106:in `block (2 levels) in top_level'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:106:in `each'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:106:in `block in top_level'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:115:in `run_with_threads'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:100:in `top_level'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:78:in `block in run'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:176:in `standard_exception_handling'
    /Users/***/.rvm/gems/ruby-2.3.0/gems/rake-10.5.0/lib/rake/application.rb:75:in `run'
    /Users/***/.rvm/gems/ruby-2.3.0@global/gems/capistrano-3.6.0/lib/capistrano/application.rb:14:in `run'
    /Users/***/.rvm/gems/ruby-2.3.0@global/gems/capistrano-3.6.0/bin/cap:3:in `<top (required)>'
    /Users/***/.rvm/gems/ruby-2.3.0/bin/cap:23:in `load'
    /Users/***/.rvm/gems/ruby-2.3.0/bin/cap:23:in `<main>'
    /Users/***/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
    /Users/***/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>'
    Tasks: TOP => production

Is anyone able provide some direction?

Answer 1

Yes, it looks like you've found a bug in the newly-released Capistrano 3.6.0. Please report the bug here: https://github.com/capistrano/capistrano/issues

The underlying problem is that Capistrano 3.6.0 is (mistakenly) incompatible with Rake < 11.0.0.

In the meantime, you can work around this issue by upgrading Rake to version 11.0.0 or higher with gem install rake or bundle update rake (depending on whether you use bundle exec for Capistrano or not).

If you are unable to upgrade Rake, downgrade Capistrano to version 3.5.0 until the bug has been fixed.

Update: Capistrano 3.6.1 has been released and restores compatibility with Rake < 11.0.0.