How to fix "undefined method `name' for Array" error when running bundled commands on Ruby 1.8.7 + Rails 2.3

On recent/fresh installations of Ruby 1.8.7 you may encounter this error why calling any bundled binary (or just bundle exec):

Copy/home/arne/.rvm/gems/ruby-1.8.7-p374@global/gems/rubygems-bundler-1.4.2/lib/rubygems-bundler/noexec.rb:75:in `setup': undefined method `name' for #<Array:0x7fe04783ef30> (NoMethodError)
  from /home/arne/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in `map'
  ...

Apparently, this is due to bundler (or maybe the rubygems-bundler that RVM supplies by default) no longer working on old Rails versions (it seems to work on applications running on Rails 3.2 + Ruby 1.8.7).

The somewhat ugly solution is to remove that global rubygems-bundler, and install it again "locally":

Copyrvm @global
gem uninstall rubygems-bundler
rvm @ # this might or might not work for you. alternatively, try "cd ."
gem install rubygems-bundler

You will get the same version of the gem, but your bundled binaries will now work again. \
Not installing rubygems-bundler after uninstallation can also be an option. See if your project works without it.

Run gem list -d rubygems-bundler to confirm it does not live in your @global gemset.