Question

I have a Rails app using Ruby 1.8.7 and I’m getting this error when running in debug mode and setting a break point:

54749: Exception in DebugThread loop: undefined method `errmsg' for #<Debugger::ControlState:0x10e3def28>
Backtrace:
/Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-0.10.4/cli/ruby-debug/command.rb:188:in `errmsg'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-0.10.4/cli/ruby-debug/commands/breakpoints.rb:81:in `execute'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide/ide_processor.rb:89:in `process_commands'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide/ide_processor.rb:86:in `catch'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide/ide_processor.rb:86:in `process_commands'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:121:in `start_control'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:103:in `initialize'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:103:in `new'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:103:in `start_control'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:65:in `start_server'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:69:in `prepare_debugger'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/lib/ruby-debug-ide.rb:83:in `debug_program'
  from: /Users/ohad/.rvm/gems/ruby-1.8.7-p371/gems/ruby-debug-ide-0.4.17.beta16/bin/rdebug-ide:109
  from: -e:1:in `load'
  from: -e:1

I’ve added ruby-debug to my Gemfile:

group :development do
  gem "inaction_mailer", '0.6', :require => 'inaction_mailer/force_load'
  gem 'ruby-debug', :require => nil
  # gem 'bullet'
  # gem "ruby-growl"
end

Answer 1

You have ruby-debug gem installed, remove it.

See this answer, only 2 debug gems are needed (versions will be different for Ruby 1.8):

ruby-debug-base (0.10.5.rc3)
ruby-debug-ide (0.4.17.beta16)