This successfully swallows the error:
This successfully swallows the error:

Error loading RubyGems plugin "/Users/jubishop/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/plugins/specific_install_plugin.rb": cannot load such file -- specific_install/version (LoadError)

which arises when running `bundle exec gem build <gemspec>` anywhere.  But general `gem specific_install` functionality remains and works great.

rdp/specific_install