FreeBSD source on GitHub and overall development model

Hi folks,

Just to figure out the overall development model for FreeBSD project (I read the project model for FreeBSD book) and have a few questions, or points to clarify I would say...

First of all, what I understand from the FreeBSD project model book is that bugzilla is used to report bugs and submit patches, but what is not included in the book is Phabricator is used in the process of reviewing submitted patches. Is my underdstanding correct here?

Another thing that I want to clarify is the role of FreeBSD GitHub repo, which is a read-only git repository. Although the repository is read-only, I see that there have been several PRs submitted so far. What is the role of FreeBSD GitHub repo in the overall development process?

Thanks in advance...
Yes Phabricator is used to allow devs to comment on patches and provide feedback before it is merged. Of course it's not purely related to Bugzilla, many of the entries on Phabricator are improvements/new features or refactoring.

As far as I'm aware the GitHub repository is purely a standalone copy for people who want to view or access the code using git or via the GitHub web interface. The devs do not use it and any issues should be submitted into Bugzilla, not the PR section in GitHub.