There might be a reason to upgrade to rubygems 1.7.x, however if you have done so by misstake and find your console swamped by thousands of deprecation warnings:
NOTE: Gem::Specification#default_executable= is deprecated with no replacement. It will be removed on or after 2011-10-01.
and you’re crying desperately for help, then you might try the following very ugly hack, which you should revert at some point in time:
First look where your rubygems are installed:
$ gem list -d rubygems
deprecate.rb file there, and make the
class method allways return
true. That’s it. Happy hacking on. And don’t
forget, that you’ll need to undo this change sometime!