Understood. However, there aren’t very many changes from 1.2.3 to 1.2.4 to 1.2.5. The changes are minor bug fixes and some deprecation warnings in preparation for 2.0.
It sounds like your app might be tied to the Rails version installed via RubyGems. If so, it’s easy to try your app with a new version of Rails and use the older version if the newer one doesn’t work well. In config/environment.rb of your project, you should be able to tweak the RAILS_GEM_VERSION. Here’s an example from one of my projects:
Specifies gem version of Rails to use when vendor/rails is not present
RAILS_GEM_VERSION = ‘1.2.5’ unless defined? RAILS_GEM_VERSION
You could install 1.2.4 via RubyGems
$ sudo gem install -y rails -v 1.2.4
Then you could set RAILS_GEM_VERSION in your app to 1.2.4. If that doesn’t work well, you could change it back to 1.2.3.
Could that work for you?