Is there a way to safely uninstall a gem installed in the shared/bundle path?

[ant0nm]

bundler/lib/capistrano/tasks/bundler.cap

Line 34 in 0a5b9dd

installed to the shared/bundle path. Gems in the development and

If possible, I want to refrain from running a full gem cleanup via bundle clean.
Is there a way to safely uninstall specific gems in the custom BUNDLE_PATH (defaults to shared/bundle)?

None of what I've tried so far seems to be working:
gem uninstall <gem_name>
gem uninstall <gem_name> --install-dir <install/path>
bundle exec gem uninstall <gem_name>

Also note that the gem in question has already been removed from the Gemfile. Now I'm just trying to actually uninstall the gem.
I keep getting the same warning:

Gem '<gem_name>' is not installed

Any idea what might be causing this? Am I missing something here?
Any help would be much appreciated!

[mattbrictson]

Hmm. I don't know how to do this with Bundler. Why do want to uninstall a specific gem? Depending on your use case, maybe there is a different approach.

Also, since this seems to be a Bundler-specific question, it might be better to ask in the Bundler project: https://github.com/rubygems/rubygems/issues/new/choose