I've just updated Google::API::Client to 0.10.
Tagged at GitHub: https://github.com/comewalk/google-api-perl-client/releases/tag/0.10
Although I announced in previous post, I renamed OAuth2 module from OAuth2::Client to Google::API::OAuth2::Client.
If you are using this module, and if you will update your environment, please change your code.
Thank you for your patience.
And I uploaded 0.10 to CPAN! (Currently the module is not available)
I will let you know Google::API::Client is available on CPAN.