I just discovered I can no longer gem push … any more and some digging led me to a need to update my RVM SSL certs.
gem push …
I ran rvm osx-ssl-certs status
rvm osx-ssl-certs status
rbenv user here, tried a couple of the solutions above but nothing worked until I uninstalled the version of ruby I had and reinstalled. So:
rbenv uninstall 2.4.3 rbenv install 2.4.3
fixed my issue and I was able to bundle.