Eliminating bundle exec

As mentioned briefly in Section 3.2.1, it is necessary in general to prefix commands such as rake or rspec with bundle exec so that the programs run in the exact gem environment specified by the Gemfile. (For technical reasons, the only exception to this is the rails command itself.) This practice is rather cumbersome, and in this section we discuss two ways to eliminate its necessity.

RVM Bundler Integration

The first and preferred method is to use the RVM Bundler integration16 to configure the Ruby Version Manager to include the proper executables automatically in the local environment. The steps are simple if somewhat mysterious. First, run these two commands:

Then run these:

Together, these commands combine RVM and Bundler magic to ensurethat commands such as rake and rspec are automatically executed in the right environment. Since these files are specific to your local setup, you should add the bundler_stubs directory to your .gitignore file (Listing 3.32).