attempting to update to ruby 1.9.2 in cygwin on Win 7 x64 with 1.8.7 installed

Newbie here, very confused.

Installed rails to cygwin using 1.8.7 and rails 3.0.3. Everything worked fine.

Wanted to test out RubyMine 3.0.1 IDE debugger but can't run debugger because 'ruby-debug-base' gem not installed. Supposedly only can install on ruby 1.9+ based on forum posts I read.

So, I built and installed(successfully) Ruby 1.9.2-p136 from source in cygwin. Used this as a guide: http://www.curphey.com/2010/05/installing-and-configuring-ruby-1-9-from-source-using-cygwin/.

I then did 'gem install rails' and 'gem update --system' afterwards. Many gems updated.

This is what I have now:

$ ruby -v ruby 1.9.2p136 (2010-12-25 revision 30365) [i386-cygwin]

$ gem env RubyGems Environment:   - RUBYGEMS VERSION: 1.4.2   - RUBY VERSION: 1.8.7 (2008-08-11 patchlevel 72) [i386-cygwin]   - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8   - RUBY EXECUTABLE: /usr/bin/ruby.exe   - EXECUTABLE DIRECTORY: /usr/bin   - RUBYGEMS PLATFORMS:     - ruby     - x86-cygwin   - GEM PATHS:      - /usr/lib/ruby/gems/1.8      - /home/cappy/.gem/ruby/1.8   - GEM CONFIGURATION:      - :update_sources => true      - :verbose => true      - :benchmark => false      - :backtrace => false      - :bulk_threshold => 1000      - :sources => ["http://rubygems.org/", "http://gems.github.com"   - REMOTE SOURCES:      - http://rubygems.org/      - http://gems.github.com

As you can see it all refers to 1.8.

NOTE: I since noticed the commented-out section in my project's Gemfile:

# To use debugger (ruby-debug for Ruby 1.8.7+, ruby-debug19 for Ruby 1.9.2+) gem 'ruby-debug' # gem 'ruby-debug19'

...so I uncommented the line and ran 'bundle install' to install it. That worked fine.

So, my big question is now that I have installed ruby 1.9.2 how do I get it to be the version that my projects use? I don't get how to switch my projects to use 1.9.2 instead of 1.8.7. Or if I need to?