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

Rails
1

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:
  • REMOTE SOURCES:

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?