I can't do anything at all in rails because of a .gemspec error, but I have no clue how to fix this

Question

I am not able to proceed with any action (even as simple as checking my rails version) because of the following error. I have no clue what I did! I appeared to have messed something up related to .gemspec, even though I don't remember doing anything strange particular. I'm new to rails, so any help would be greatly appreciated.

Here is part of the error because it was too long to include all of it:

---

$ rails -v WARNING:  #<ArgumentError: Illformed requirement ["#<YAML::Syck::DefaultKey:0x10ac34e60> 3.2.0"]>
# -*- encoding: utf-8 -*-

Gem::Specification.new do |s|   s.name = %q{actionmailer}   s.version
= "3.2.0"

  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=   s.authors = ["David Heinemeier Hansson"]   s.date = %q{2012-01-20}   s.description = %q{Email on Rails. Compose, deliver, receive, and test emails using the familiar controller/view pattern. First-class support for multipart email and attachments.}   s.email = %q{david@loudthinking.com}   s.files = ["CHANGELOG.md", "README.rdoc", "MIT-LICENSE", "lib/action_mailer/base.rb", "lib/action_mailer/collector.rb", "lib/action_mailer/delivery_methods.rb", "lib/action_mailer/log_subscriber.rb", "lib/action_mailer/mail_helper.rb", "lib/action_mailer/railtie.rb", "lib/action_mailer/test_case.rb", "lib/action_mailer/test_helper.rb", "lib/action_mailer/version.rb", "lib/action_mailer.rb", "lib/rails/generators/mailer/mailer_generator.rb", "lib/rails/generators/mailer/templates/mailer.rb", "lib/rails/generators/mailer/USAGE"]   s.homepage = %q{http://www.rubyonrails.org}   s.require_paths = ["lib"]   s.required_ruby_version = Gem::Requirement.new(">= 1.8.7")   s.requirements = ["none"]   s.rubygems_version = %q{1.3.6}   s.summary
= %q{Email composition, delivery, and receiving framework (part of Rails).}

  if s.respond_to? :specification_version then
    current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION
    s.specification_version = 3

    if Gem::Version.new(Gem::RubyGemsVersion) >= Gem::Version.new('1.2.0') then
      s.add_runtime_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ac34e60> 3.2.0"])
      s.add_runtime_dependency(%q<mail>, ["~> 2.4.0"])
    else
      s.add_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ac34e60> 3.2.0"])
      s.add_dependency(%q<mail>, ["~> 2.4.0"])
    end   else
    s.add_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ac34e60> 3.2.0"])
    s.add_dependency(%q<mail>, ["~> 2.4.0"])   end end WARNING:  Invalid .gemspec format in '/Library/Ruby/Gems/1.8/specifications/actionmailer-3.2.0.gemspec' WARNING:  #<ArgumentError: Illformed requirement ["#<YAML::Syck::DefaultKey:0x10adcc2f0> 3.2.0"]>
# -*- encoding: utf-8 -*-

Gem::Specification.new do |s|   s.name = %q{actionpack}   s.version = "3.2.0"

  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=   s.authors = ["David Heinemeier Hansson"]   s.date = %q{2012-01-20}   s.description = %q{Web apps on Rails. Simple, battle-tested conventions for building and testing MVC web applications. Works with any Rack-compatible server.}   s.email = 

...

%q{1.3.6}   s.summary = %q{Tools for creating, working with, and running Rails applications.}

  if s.respond_to? :specification_version then
    current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION
    s.specification_version = 3

    if Gem::Version.new(Gem::RubyGemsVersion) >= Gem::Version.new('1.2.0') then
      s.add_runtime_dependency(%q<rake>, [">= 0.8.7"])
      s.add_runtime_dependency(%q<thor>, ["~> 0.14.6"])
      s.add_runtime_dependency(%q<rack-ssl>, ["~> 1.3.2"])
      s.add_runtime_dependency(%q<rdoc>, ["~> 3.4"])
      s.add_runtime_dependency(%q<activesupport>, ["#<YAML::Syck::DefaultKey:0x10ab088e8> 3.2.0"])
      s.add_runtime_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ab01bd8> 3.2.0"])
    else
      s.add_dependency(%q<rake>, [">= 0.8.7"])
      s.add_dependency(%q<thor>, ["~> 0.14.6"])
      s.add_dependency(%q<rack-ssl>, ["~> 1.3.2"])
      s.add_dependency(%q<rdoc>, ["~> 3.4"])
      s.add_dependency(%q<activesupport>, ["#<YAML::Syck::DefaultKey:0x10ab088e8> 3.2.0"])
      s.add_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ab01bd8> 3.2.0"])
    end   else
    s.add_dependency(%q<rake>, [">= 0.8.7"])
    s.add_dependency(%q<thor>, ["~> 0.14.6"])
    s.add_dependency(%q<rack-ssl>, ["~> 1.3.2"])
    s.add_dependency(%q<rdoc>, ["~> 3.4"])
    s.add_dependency(%q<activesupport>, ["#<YAML::Syck::DefaultKey:0x10ab088e8> 3.2.0"])
    s.add_dependency(%q<actionpack>, ["#<YAML::Syck::DefaultKey:0x10ab01bd8> 3.2.0"])   end end WARNING:  Invalid .gemspec format in '/Library/Ruby/Gems/1.8/specifications/railties-3.2.0.gemspec' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:230:in `activate': can't activate rack (~> 1.3.5, runtime) for ["actionpack-3.1.3", "rails-3.1.3"], already activated rack-1.4.1 for ["rack-cache-1.1", "actionpack-3.1.3", "rails-3.1.3"] (Gem::LoadError)     from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:246:in `activate'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:245:in `each'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:245:in `activate'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:246:in `activate'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:245:in `each'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:245:in `activate'  from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:1056:in `gem'  from /usr/bin/rails:18

Answer 1

You will need to try and reinstall/upgrade Rails and RubyGems, if that doesn't fix the issue, you may need to reinstall ruby, as I had to do when I ran into this error.

To update rubygems:

sudo gem install rubygems-update
sudo update_rubygems