unicode_utils gema no se instalará - ruby-on-rails, ruby, unicode, ruby-on-rails-3.2, ruby-1.9.2

Estoy recibiendo este error en una instalación de paquete (esto es mientras uso Ruby 1.9.2 (también he probado 1.9.1) y Rails 3.2.11

Installing unicode_utils (1.4.0) /usr/lib/ruby/vendor_ruby/1.8/rubygems/installer.rb:388:in `ensure_required_ruby_version_met": unicode_utils requires Ruby version >= 1.9.1. (Gem::InstallError)
from /usr/lib/ruby/vendor_ruby/1.8/rubygems/installer.rb:156:in `install"
from /usr/lib/ruby/vendor_ruby/bundler/source.rb:101:in `install"
from /usr/lib/ruby/vendor_ruby/bundler/rubygems_integration.rb:78:in `preserve_paths"
from /usr/lib/ruby/vendor_ruby/bundler/source.rb:91:in `install"
from /usr/lib/ruby/vendor_ruby/bundler/installer.rb:58:in `run"
from /usr/lib/ruby/vendor_ruby/bundler/rubygems_integration.rb:93:in `with_build_args"
from /usr/lib/ruby/vendor_ruby/bundler/installer.rb:57:in `run"
from /usr/lib/ruby/vendor_ruby/bundler/spec_set.rb:12:in `each"
from /usr/lib/ruby/vendor_ruby/bundler/spec_set.rb:12:in `each"
from /usr/lib/ruby/vendor_ruby/bundler/installer.rb:49:in `run"
from /usr/lib/ruby/vendor_ruby/bundler/installer.rb:8:in `install"
from /usr/lib/ruby/vendor_ruby/bundler/cli.rb:222:in `install"
from /usr/lib/ruby/vendor_ruby/bundler/vendor/thor/task.rb:22:in `send"
from /usr/lib/ruby/vendor_ruby/bundler/vendor/thor/task.rb:22:in `run"
from /usr/lib/ruby/vendor_ruby/bundler/vendor/thor/invocation.rb:118:in `invoke_task"
from /usr/lib/ruby/vendor_ruby/bundler/vendor/thor.rb:246:in `dispatch"
from /usr/lib/ruby/vendor_ruby/bundler/vendor/thor/base.rb:389:in `start"
from /usr/bin/bundle:13

Respuestas

Está claro en el mensaje de error y estoy seguro de que otros lo vieron muy claramente: Installing unicode_utils (1.4.0) /usr/lib/ruby/vendor_ruby/1.8/rubygems/installer.rb:388:in `ensure_required_ruby_version_met": unicode_utils requires Ruby version >= 1.9.1. (Gem::InstallError)

Estás utilizando una versión global de Ruby 1.8. UnicodeUtils trabaja con Ruby 1.9.1 o posterior

Para RVM:

$ rvm --default use 1.9.2

En tu Gemfile:

gem "unicode_utils", "~> 1.4.0"

La instalación desde el terminal funciona de la misma manera.