ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError) too many connection resets
I was getting this error when trying to install the gem https://au-m.rubygems.org/quick/Marshal.4.8/turbolinks-2.3.0.gemspec.rz. It looks like it was a temporary issue with the server, and running gem install turbolinks -v '2.3.0' --source "http://production.s3.rubygems.org" didn't make any difference.
One workaround is to download the gem file manually (e.g. http://au-m.rubygems.org/gems/turbolinks-2.3.0.gem --> http://production.s3.rubygems.org/gems/turbolinks-2.3.0.gem) and then gem install turbolinks-2.3.0.gem.