gem installation prompt forces dep to hang forever

[xxuejie]

In rbenv environment, when installing certain gems(rake, for example), if we have an executable conflict, a prompt will be showed:

$ gem install capistrano
Fetching: net-ssh-2.7.0.gem (100%)
Successfully installed net-ssh-2.7.0
Fetching: net-scp-1.1.2.gem (100%)
Successfully installed net-scp-1.1.2
Fetching: tins-0.13.1.gem (100%)
Successfully installed tins-0.13.1
Fetching: term-ansicolor-1.2.2.gem (100%)
Successfully installed term-ansicolor-1.2.2
Fetching: sshkit-1.3.0.gem (100%)
Successfully installed sshkit-1.3.0
Fetching: rake-10.1.0.gem (100%)
rake's executable "rake" conflicts with /home/vagrant/.rbenv/versions/2.0.0-p353/bin/rake
Overwrite the executable? [yN]

However, if we are installing this gem using dep install, we will have no chance of seeing the prompt, the installation will instead hang there forever.

Anyway we can fix this? Thanks!