Ruby's RVM weird "@global" symlink issue

Question

In my Gruntfile.js, I have a following Compass task with 2 dependencies:

    compass: {
        parent: {
            options: {
                // ... other options ... 
                require: [
                    'modular-scale',
                    'susy'
                ]
                // force: true
            }
        },
   }

After a clean install of Yosemite, Grunt task at existing project throws following error on each dependency (no matter if modular-scale or susy):

LoadError on line ["179"] of /Users/Cibulka/.rvm/gems/ruby-2.1.2/gems/compass-core-1.0.1/lib/compass/configuration/data.rb: cannot load such file -- modular-scale

I am using RVM for Ruby but to be honest, I do not understand the most of it (I just need my Sass to work!). This is my gem list:

bigdecimal (1.2.5, 1.2.4)
bundler (1.7.4, 1.6.2)
bundler-unload (1.0.2)
capistrano (3.2.1)
capistrano-composer (0.0.4)
chunky_png (1.3.3)
colorize (0.7.3)
compass (1.0.1)
compass-core (1.0.1)
compass-import-once (1.0.5)
executable-hooks (1.3.2)
ffi (1.9.6)
gem-wrappers (1.2.7, 1.2.4)
i18n (0.6.11)
io-console (0.4.2)
json (1.8.1)
minitest (5.4.2, 4.7.5)
modular-scale (2.0.5)
multi_json (1.10.1)
net-scp (1.2.1)
net-ssh (2.9.1)
power_assert (0.1.4)
psych (2.0.6, 2.0.5)
rake (10.3.2, 10.1.0)
rb-fsevent (0.9.4)
rb-inotify (0.9.5)
rdoc (4.1.2, 4.1.0)
rubygems-bundler (1.4.4)
rubygems-update (2.4.2)
rvm (1.11.3.9)
sass (3.4.6)
sshkit (1.5.1)
susy (2.1.3)
test-unit (3.0.2, 2.1.2.0)

Note please, that both Susy and Modular-Scale gems are present.

My $PATH:

/Users/Cibulka/.rvm/gems/ruby-2.1.2/bin:
/Users/Cibulka/.rvm/gems/ruby-2.1.2@global/bin:
/Users/Cibulka/.rvm/rubies/ruby-2.1.2/bin:
/usr/local/sbin:
/usr/local/bin:
/usr/local/bin:
/usr/bin:/bin:
/usr/sbin:
/sbin:
/Users/Cibulka/.rvm/bin

Any idea what am I doing wrong? There are lost of similar questions out there, but none would seem to work for me (either there were very different circumnstances or the answer was that user forgot to install the gem).

Thank you in advance!

Edit

Okay, after some further tinkering I've managed to find a solution.

Under /Users/Cibulka/.rvm/gems directory I've deleted symlink ruby-2.1.2@global pointing to /Users/Cibulka/.rvm/rubies/ruby-2.1.2/lib/ruby/gems/2.1.0. For some reason, it fixed things. I definitely did not put the symlink there myself. :)

My question stands - why that worked and what was the symlink doing there in the first place? Also, is deleting the symlink the solution or just removing the symptom of deeper problem?

Thanks!