How to update my rails 3.0.0 beta 4 app to rails 3.0.0 RC and eventually to Rails 3?

My first problem is a bundler conflict

$ bundle install
Fetching source index from ht开发者_开发问答tp://rubygems.org/
No compatible versions could be found for required dependencies:
    Conflict on: "bundler":
    * bundler (0.9.26) activated by bundler (= 0.9.26, runtime)
    * bundler (>= 1.0.0.rc.1, runtime) required in Gemfile
    All possible versions of origin requirements conflict.

After I figure that out,

Is there anything I need to do to change my Beta 4 Rails app to work on the RC?

You may want to check out upgrading Rails from beta4 to RC. It's mentioning changes to Bundler and to your app's files (like config/* and Rakefile).

There are also important changes to bundler usage (like the default install location is now system-wide, not local). Yehuda gives a great overview of best practices:

Deployment
When deploying, we strongly recommend that you isolate your gems into a local path (using bundle install path --disable-shared-gems). The final version of bundler will come with a --production flag, encapsulating all of the best deployment practices.

For now, please follow the following recommendations (described using Capistrano concepts):

1. Make sure to always check in a Gemfile.lock that is up to date. This means that after modifying your Gemfile, you should ALWAYS run bundle install.

2. Symlink the vendor/bundle directory into the application’s shared location (symlink release_path/current/vendor/bundle to release_path/shared/bundled_gems)

3. Install your bundle by running bundle install vendor/bundle --disable-shared-gems

For more information, read this blog post.

gem install bundler --pre
bundle install