Bundler will automatically install any dependencies for the specified gems, however it doesn\'t output which dependencies map to which gems in the standard output. That info
A less exciting, but equally effective way is to just do:
gem dep
which will generate a Gemfile.lock style output with dependency information. You could pipe this output to less:
gem dep | less
Or, if you are searching for a failing dependency, you could grep it with some context. For instance, to find out where my failing Thin dependency was coming from (fails with JRuby), I did:
gem dep | grep -C 15 thin