rails: Rails 3.1.1 fails with Psych 1.2.2 in Ruby 1.9.3p0

Details below. Thank you.

/tmp/foobar> ruby -v                                                                                          12:35PM
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]

/tmp/foobar> rails -v                                                                                         12:35PM
Rails 3.1.1

/tmp/foobar> bundle --version                                                                                 12:35PM
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:93: warning: already initialized constant VERSION
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:96: warning: already initialized constant LIBYAML_VERSION
Bundler version 1.0.21

/tmp> rails new foobar                                                                                        12:36PM
      create  
      create  README
      create  Rakefile
      create  config.ru
      create  .gitignore
      create  Gemfile
      create  app
      create  app/assets/images/rails.png
      create  app/assets/javascripts/application.js
      create  app/assets/stylesheets/application.css
      create  app/controllers/application_controller.rb
      create  app/helpers/application_helper.rb
      create  app/mailers
      create  app/models
      create  app/views/layouts/application.html.erb
      create  app/mailers/.gitkeep
      create  app/models/.gitkeep
      create  config
      create  config/routes.rb
      create  config/application.rb
      create  config/environment.rb
      create  config/environments
      create  config/environments/development.rb
      create  config/environments/production.rb
      create  config/environments/test.rb
      create  config/initializers
      create  config/initializers/backtrace_silencers.rb
      create  config/initializers/inflections.rb
      create  config/initializers/mime_types.rb
      create  config/initializers/secret_token.rb
      create  config/initializers/session_store.rb
      create  config/initializers/wrap_parameters.rb
      create  config/locales
      create  config/locales/en.yml
      create  config/boot.rb
      create  config/database.yml
      create  db
      create  db/seeds.rb
      create  doc
      create  doc/README_FOR_APP
      create  lib
      create  lib/tasks
      create  lib/tasks/.gitkeep
      create  lib/assets
      create  lib/assets/.gitkeep
      create  log
      create  log/.gitkeep
      create  public
      create  public/404.html
      create  public/422.html
      create  public/500.html
      create  public/favicon.ico
      create  public/index.html
      create  public/robots.txt
      create  script
      create  script/rails
      create  test/fixtures
      create  test/fixtures/.gitkeep
      create  test/functional
      create  test/functional/.gitkeep
      create  test/integration
      create  test/integration/.gitkeep
      create  test/unit
      create  test/unit/.gitkeep
      create  test/performance/browsing_test.rb
      create  test/test_helper.rb
      create  tmp/cache
      create  tmp/cache/assets
      create  vendor/assets/stylesheets
      create  vendor/assets/stylesheets/.gitkeep
      create  vendor/plugins
      create  vendor/plugins/.gitkeep
         run  bundle install
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:93: warning: already initialized constant VERSION
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:96: warning: already initialized constant LIBYAML_VERSION
Fetching source index for http://rubygems.org/
Using rake (0.9.2.2) 
Using multi_json (1.0.3) 
Using activesupport (3.1.1) 
Using builder (3.0.0) 
Using i18n (0.6.0) 
Using activemodel (3.1.1) 
Using erubis (2.7.0) 
Using rack (1.3.5) 
Using rack-cache (1.1) 
Using rack-mount (0.8.3) 
Using rack-test (0.6.1) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.0.3) 
Using actionpack (3.1.1) 
Using mime-types (1.17.2) 
Using polyglot (0.3.3) 
Using treetop (1.4.10) 
Using mail (2.3.0) 
Using actionmailer (3.1.1) 
Using arel (2.2.1) 
Using tzinfo (0.3.30) 
Using activerecord (3.1.1) 
Using activeresource (3.1.1) 
Using ansi (1.3.0) 
Using bundler (1.0.21) 
Using coffee-script-source (1.1.2) 
Using execjs (1.2.9) 
Using coffee-script (2.2.0) 
Using rack-ssl (1.3.2) 
Using json (1.6.1) 
Using rdoc (3.11) 
Using thor (0.14.6) 
Using railties (3.1.1) 
Using coffee-rails (3.1.1) 
Using jquery-rails (1.0.16) 
Using rails (3.1.1) 
Using sass (3.1.10) 
Using sass-rails (3.1.4) 
Using sqlite3 (1.3.4) 
Using turn (0.8.3) 
Using uglifier (1.0.4) 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

/tmp> cd foobar                                                                                               12:36PM

/tmp/foobar> bundle exec rails runner 'puts :ok'                                                              12:39PM
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:93: warning: already initialized constant VERSION
/home/sunny/app/rubygems/gems/psych-1.2.2/lib/psych.rb:96: warning: already initialized constant LIBYAML_VERSION
/usr/lib/ruby/1.9.1/x86_64-linux/psych.so: warning: already initialized constant ANY
/usr/lib/ruby/1.9.1/x86_64-linux/psych.so: warning: already initialized constant UTF8
/usr/lib/ruby/1.9.1/x86_64-linux/psych.so: warning: already initialized constant UTF16LE
/usr/lib/ruby/1.9.1/x86_64-linux/psych.so: warning: already initialized constant UTF16BE
/usr/lib/ruby/1.9.1/psych/nodes/stream.rb:12: warning: already initialized constant ANY
/usr/lib/ruby/1.9.1/psych/nodes/stream.rb:15: warning: already initialized constant UTF8
/usr/lib/ruby/1.9.1/psych/nodes/stream.rb:18: warning: already initialized constant UTF16LE
/usr/lib/ruby/1.9.1/psych/nodes/stream.rb:21: warning: already initialized constant UTF16BE
/usr/lib/ruby/1.9.1/psych/nodes/sequence.rb:42: warning: already initialized constant ANY
/usr/lib/ruby/1.9.1/psych/nodes/sequence.rb:45: warning: already initialized constant BLOCK
/usr/lib/ruby/1.9.1/psych/nodes/sequence.rb:48: warning: already initialized constant FLOW
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:9: warning: already initialized constant ANY
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:12: warning: already initialized constant PLAIN
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:15: warning: already initialized constant SINGLE_QUOTED
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:18: warning: already initialized constant DOUBLE_QUOTED
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:21: warning: already initialized constant LITERAL
/usr/lib/ruby/1.9.1/psych/nodes/scalar.rb:24: warning: already initialized constant FOLDED
/usr/lib/ruby/1.9.1/psych/nodes/mapping.rb:16: warning: already initialized constant ANY
/usr/lib/ruby/1.9.1/psych/nodes/mapping.rb:19: warning: already initialized constant BLOCK
/usr/lib/ruby/1.9.1/psych/nodes/mapping.rb:22: warning: already initialized constant FLOW
/usr/lib/ruby/1.9.1/psych/visitors/visitor.rb:10: warning: already initialized constant DISPATCH
/usr/lib/ruby/1.9.1/psych/scalar_scanner.rb:8: warning: already initialized constant TIME
/usr/lib/ruby/1.9.1/psych/parser.rb:33:in `<class:Parser>': superclass mismatch for class Mark (TypeError)
    from /usr/lib/ruby/1.9.1/psych/parser.rb:32:in `<module:Psych>'
    from /usr/lib/ruby/1.9.1/psych/parser.rb:1:in `<top (required)>'
    from /usr/lib/ruby/1.9.1/psych.rb:7:in `require'
    from /usr/lib/ruby/1.9.1/psych.rb:7:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/activesupport-3.1.1/lib/active_support/ordered_hash.rb:2:in `require'
    from /home/sunny/app/rubygems/gems/activesupport-3.1.1/lib/active_support/ordered_hash.rb:2:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/activesupport-3.1.1/lib/active_support/ordered_options.rb:1:in `require'
    from /home/sunny/app/rubygems/gems/activesupport-3.1.1/lib/active_support/ordered_options.rb:1:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/configuration.rb:2:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/configuration.rb:2:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/railtie.rb:2:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/railtie.rb:2:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/engine.rb:1:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/engine.rb:1:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/plugin.rb:1:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/plugin.rb:1:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/application.rb:4:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/application.rb:4:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails.rb:10:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails.rb:10:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/all.rb:1:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/all.rb:1:in `<top (required)>'
    from /tmp/foobar/config/application.rb:3:in `require'
    from /tmp/foobar/config/application.rb:3:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/commands/runner.rb:39:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/commands/runner.rb:39:in `<top (required)>'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/commands.rb:63:in `require'
    from /home/sunny/app/rubygems/gems/railties-3.1.1/lib/rails/commands.rb:63:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'
exit 1