How to downgrade bundler or upgrade rails?

Question

I added omniauth gem to my gemfile and tried to run bundle install, but got a message about incompatibility of rails and bundler versions. I tried to update rails, but got messages about incompatibility with other gems. How can I downgrade bundler to 1.0?

$ bundle install Fetching gem metadata from http://rubygems.org/...... Fetching gem metadata from http://rubygems.org/.. Bundler could not find compatible versions for gem "bundler":   In Gemfile:     rails (= 3.0.0) ruby depends on       bundler (~> 1.0.0) ruby    Current Bundler version:     bundler (1.1.1)  This Gemfile requires a different version of Bundler. Perhaps you need to update Bundler by running `gem install bundler`? 

and

$ bundle update rails Fetching gem metadata from http://rubygems.org/...... Fetching gem metadata from http://rubygems.org/.. Bundler could not find compatible versions for gem "bundler":   In Gemfile:     factory_girl_rails (>= 0) ruby depends on       bundler (~> 1.0.0) ruby    Current Bundler version:     bundler (1.1.1) 

Answer 1

Try the following commands:

gem uninstall bundler gem install bundler --version '1.0.0' 

Answer 2

To install downgraded version of bundler, try:

gem install bundler --version '<= 0.10.6' 

so you could have both version installed (check: gem list bundler/bundler _0.9.26_ -v), then run using that specific version, e.g.:

bundle _0.9.26_ install 

Learn more: How to upgrade/downgrade Rubygems at rubyforge