Running vim-ruby-debugger on MacVim in OS X 10.10 - ruby-on-rails

Question

Spent all day trying to make it works.
Installed like described in readme.
This shell call:
rdebug-vim --file /Users/aleksandrkunin/.vim/tmp/ruby_debugger --output /Users/aleksandrkunin/.vim/tmp/ruby_debugger_output --socket /var/folders/p9/dq06c2dn72nbbk45qdc5yx1h0000gp/T/vLSSici/17 --logger_file /Users/aleksandrkunin/.vim/tmp/ruby_debugger_log --debug_mode 0 --vim_executable mvim --vim_servername VIM --separator ++vim-ruby-debugger-separator++ -- '/Users/aleksandrkunin/Documents/rails_projects/tracks_dev/script/rails' server
Cause this error:
Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/byebug/commands/frame.rb:12:in `alias_method': undefined method `get_pr_arguments' for module `Byebug::FrameFunctions' (NameError)
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/byebug/commands/frame.rb:12:in `<module:FrameFunctions>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/byebug/commands/frame.rb:2:in `<module:Byebug>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/byebug/commands/frame.rb:1:in `<top (required)>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/debugger_xml.rb:5:in `block in <top (required)>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/debugger_xml.rb:5:in `each'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/lib/debugger_xml.rb:5:in `<top (required)>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/debugger-xml-0.4.1/bin/rdebug-vim:15:in `<top (required)>'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/bin/rdebug-vim:23:in `load'
from /Users/aleksandrkunin/.rbenv/versions/2.1.2/bin/rdebug-vim:23:in `<main>'
Is it possible to run? Is there another way for visual debugging in VIM?

Answer 1

I think the problem is that you're trying to use a gem that says it's for Ruby >= 1.9 with Ruby 2+.
rdebug does not work with Ruby 2.0+, only with Ruby in the 1.9 range. The documentation is confusing but that's how it is.
... This is a new version of the plugin, which uses debugger-xml gem, and works only with Ruby >= 1.9....
Look at the revision history of rdebug and you can see it hasn't been updated in a while.
With 2.1.1 you're using byebug, which doesn't implement the necessary call to work with Vim, hence the message:
undefined method `get_pr_arguments' for module `Byebug::FrameFunctions' (NameError)
Your choices are:
Revert to Ruby 1.9.3-p551, which is the latest of that series and install rdebug.
Stop trying to use vim-rdebug and learn to use byebug in its standalone mode, which is a more traditional debugger and works nicely. (Alternately you could use Pry and pry-debug.)