Ошибка при установке отладчика (1.6.8), и Bundler не может продолжаться. Убедитесь, что `gem install debugger -v '1.6.8``

Кажется, что при установке отладчика gem install debugger -v '1.6.8' эффект рекурсии говорит о успешной установке, но сообщение появляется снова, когда я делаю bundle install или bundle update

|20:15:37| ~ gem install debugger -v '1.6.8'
Building native extensions.  This could take a while...
Successfully installed debugger-1.6.8
Parsing documentation for debugger-1.6.8
unable to convert "\xCF" from ASCII-8BIT to UTF-8 for lib/ruby_debug.bundle, skipping
1 gem installed
|20:15:55| ~ bundle install
Fetching gem metadata from https://rubygems.org/.......
Fetching additional metadata from https://rubygems.org/..
Resolving dependencies......
Using rake 10.3.2
Using Ascii85 1.0.2
Using i18n 0.6.9

...

Using coffee-script 2.2.0
Using coffee-rails 3.2.2
Using colored 1.2
Using commonjs 0.2.7
Using coolline 0.4.4
Using debugger-ruby_core_source 1.3.5

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby extconf.rb
checking for rb_method_entry_t.called_id in method.h... no
checking for rb_control_frame_t.method_id in method.h... no
checking for rb_method_entry_t.called_id in method.h... no
checking for rb_control_frame_t.method_id in method.h... no
checking for rb_method_entry_t.called_id in method.h... yes
checking for vm_core.h... yes
checking for iseq.h... no
Makefile creation failed
*************************************************************

  NOTE: If your headers were not found, try passing
        --with-ruby-include=PATH_TO_HEADERS

*************************************************************

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby
    --with-ruby-dir
    --without-ruby-dir
    --with-ruby-include
    --without-ruby-include=${ruby-dir}/include
    --with-ruby-lib
    --without-ruby-lib=${ruby-dir}/

extconf failed, exit code 1

Gem files will remain installed in /var/folders/mp/tl8cpc_j0vd504t3npnqxzl00000gn/T/bundler20140630-67837-rxj9rk/debugger-1.6.8/gems/debugger-1.6.8 for inspection.
Results logged to /var/folders/mp/tl8cpc_j0vd504t3npnqxzl00000gn/T/bundler20140630-67837-rxj9rk/debugger-1.6.8/extensions/universal-darwin-13/2.0.0/debugger-1.6.8/gem_make.out
An error occurred while installing debugger (1.6.8), and Bundler cannot continue.
Make sure that `gem install debugger -v '1.6.8'` succeeds before bundling.
|20:17:56| ~

Я пробовал bundle update debugger-ruby_core_source и rm Gemfile.lock, затем bundle install