undefined method `map' for nil:NilClass

[ghost]

Hello. In running rubocop today, I received an error message where my code had previously passed a few days before (presumably with the .33 version). I admit I am relatively new to the Ruby eco-system and do not have enough knowledge to be able to troubleshoot so I figured I would submit an issue.

Thank you ever so much and thanks for a wonderful product!

$ bundle exec rake style
Running RuboCop...
undefined method `map' for nil:NilClass
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/psych.rb:287:in `safe_load'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/config_loader.rb:151:in `yaml_safe_load'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/config_loader.rb:138:in `load_yaml_configuration'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/config_loader.rb:27:in `load_file'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/config_loader.rb:85:in `configuration_from_file'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/config_store.rb:40:in `for'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/target_finder.rb:112:in `excluded_dirs'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/target_finder.rb:90:in `find_files'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/target_finder.rb:60:in `target_files_in_dir'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/target_finder.rb:31:in `find'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/runner.rb:45:in `find_target_files'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/runner.rb:29:in `run'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/cli.rb:26:in `run'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/rake_task.rb:50:in `run_cli'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/rake_task.rb:38:in `run_main_task'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/rake_task.rb:30:in `block (2 levels) in initialize'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/file_utils_ext.rb:58:in `verbose'
/home/travis/.rvm/gems/ruby-2.2.2/gems/rubocop-0.34.0/lib/rubocop/rake_task.rb:26:in `block in initialize'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:240:in `call'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:240:in `block in execute'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:235:in `each'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:235:in `execute'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:179:in `block in invoke_with_call_chain'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:172:in `invoke_with_call_chain'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:201:in `block in invoke_prerequisites'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:199:in `each'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:199:in `invoke_prerequisites'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:178:in `block in invoke_with_call_chain'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:172:in `invoke_with_call_chain'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/task.rb:165:in `invoke'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:150:in `invoke_task'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `block (2 levels) in top_level'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `each'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:106:in `block in top_level'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:115:in `run_with_threads'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:100:in `top_level'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:78:in `block in run'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:176:in `standard_exception_handling'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/application.rb:75:in `run'
/home/travis/.rvm/rubies/ruby-2.2.2/lib/ruby/gems/2.2.0/gems/rake-10.4.2/bin/rake:33:in `<top (required)>'
/home/travis/.rvm/gems/ruby-2.2.2/bin/rake:23:in `load'
/home/travis/.rvm/gems/ruby-2.2.2/bin/rake:23:in `<main>'
/home/travis/.rvm/gems/ruby-2.2.2/bin/ruby_executable_hooks:15:in `eval'
/home/travis/.rvm/gems/ruby-2.2.2/bin/ruby_executable_hooks:15:in `<main>'
RuboCop failed!

[ghost]

I have determined that rolling back to version 0.33.0 in my Gemfile via gem 'rubocop', '~> 0.33.0', require: false does not throw the error.

[brint]

We've seen this as well with tests since 0.34.0 was released. We have pinned back to 0.33.0 for now. In our Rakefile, we have a line like this to run our Ruby style checks which generates the same error that @st-isidore-de-seville is seeing:

RuboCop::RakeTask.new(:ruby)

Example Rakefile (from a Chef cookbook):

require 'bundler/setup'
require 'rspec/core/rake_task'
require 'rubocop/rake_task'
require 'foodcritic'
require 'kitchen'

# Style tests. Rubocop and Foodcritic
namespace :style do
  desc 'Run Chef style checks'
  FoodCritic::Rake::LintTask.new(:chef) do |t|
    t.options = {
      search_gems: true,
      fail_tags: %w(any),
      # FC015: Consider converting definition to a LWRP (allow definitions without complaining)
      tags: %w(~FC015 ~FC041),
      chef_version: '12.3.0' # 12.2 was not valid - https://github.com/acrmp/foodcritic/issues/221
    }
  end

  desc 'Run Ruby style checks'
  RuboCop::RakeTask.new(:ruby)
end

desc 'Run all style checks'
task style: ['style:chef', 'style:ruby']

# Integration tests. Kitchen.ci
task :integration do
  desc 'Run Test Kitchen'
  Kitchen.logger = Kitchen.default_file_logger
  @loader = Kitchen::Loader::YAML.new(
    local_config: ENV['KITCHEN_LOCAL_YAML']
  )
  if ENV['KITCHEN_CONCURRENCY_DISABLE']
    Kitchen::Config.new(loader: @loader).instances.each do |instance|
      instance.test(:always)
    end
  else
    config = Kitchen::Config.new(loader: @loader)
    concurrency = config.instances.size
    queue = Queue.new
    config.instances.each { |i| queue << i }
    concurrency.times { queue << nil }
    threads = []
    concurrency.times do
      threads << Thread.new do
        while instance = queue.pop
          instance.send('test')
        end
      end
    end
    threads.map(&:join)
  end
end

# Default
task default: ['style', 'integration']

[bbatsov]

The fix is merged. Play with it and if everything looks good I'll cut a bugfix release tomorrow.

[ghost]

Thanks @bbatsov and @maxjacobson!

[martinb3]

👍 I'd love to see this released as well. It's breaking CI on many of our Chef cookbooks.