RubyMine / IDEA ruby​​调试器无法在bundler模​​式下加载linecache gem

Question

Start debugger within bundler (check the "Run the script in bundle context" option in the run target's bundler tab) in IDEA 13 (and earlier version eg 11) Ruby, I always get

/Users/me/.rvm/rubies/ree-1.8.7-2012.02/bin/ruby -e at_exit{sleep(1)};$stdout.sync=true;$stderr.sync=true;load($0=ARGV.shift) /Users/me/.rvm/gems/ree-1.8.7-2012.02/gems/ruby-debug-ide-0.4.22/bin/rdebug-ide --disable-int-handler --port 58100 --dispatcher-port 58101 -- /Users/me/railproj/script/spec --format specdoc spec/**/any_ruby_spec.rb
/Users/me/.rvm/gems/ree-1.8.7-2012.02/gems/ruby-debug-base-0.10.5.rc9/lib/ruby-debug-base.rb:3:in `require': no such file to load -- linecache (LoadError)
    from /Users/me/.rvm/gems/ree-1.8.7-2012.02/gems/ruby-debug-base-0.10.5.rc9/lib/ruby-debug-base.rb:3
    from /Users/me/Library/Application Support/IntelliJIdea13/ruby/rb/gems/debug_preloader.rb:2:in `require'
    from /Users/me/Library/Application Support/IntelliJIdea13/ruby/rb/gems/debug_preloader.rb:2

The linecache gem is installed properly

$ gem which linecache
/Users/me/.rvm/gems/ree-1.8.7-2012.02/gems/linecache-0.46/lib/linecache.rb

Putting the linecache in Gemfile does not help at all.

But launch debugger for the same run target without bundler (unchecking "Run the script in bundle context") works. Of course, one would get gem conflict easily with bundler context.

How can this be fixed?

Answer 1

I found the solution / work around: just add

require 'rubygems'

to the first line of ruby-debug-base.rb (making sure adding to the right one used by RM/Idea as there can be multiple versions.)

but I still don't know why it would just work without the bundler option. I feel the opposite should be the case.

Answer 2

For a cleaner fix than the one provided by Hacking Bear, that avoids having to hack at third-party Gems:

Navigate to: Run > Edit Configurations

Prefix the Ruby arguments line with: -r rubygems

From the Ruby man-page:

   -r library
          Causes Ruby to load the library using require.  It is useful when using -n or -p.