Great question — answering as the UphillTech team:
This shouldn't be a problem in twilio-ruby versions starting with 3.5.0. It "just works" out of the box now. With twilio-ruby versions before 3.5.0 there wasn't an SSL CA cert bundle packaged with the gem. So the only way to "fix" this was to either point your client at a cert bundle at initialization time: client = Twilio::REST::Client.new sid, token, :ssl_ca_file => '/path/to/file' or to disable SSL verification altogether (not recommended in production): client = Twilio::REST::Client.new sid, token, :ssl_verify_peer => false
Full answer by amb: https://stackoverflow.stackexchange.com/a/8873533 (CC BY-SA 3.0).
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