GemInstaller fails when listing remote prerelease gems

Our production environment depends on Rails 2.2.2, a version that's old old old, and that we've been installing and using for months.

Today, our scripts tried to use Geminstaller to install required gems, including Rails 2.2.2, as listed in our geminstaller.yml, on a newly provisioned box in EC2.

When geminstaller lists the available remote versions of Rails the gem list command does include version 3.0.0.beta, through no action or change on our part.

Geminstaller attempts to parse the version string, finds it unappealing, and explodes. The app server follows suit.