How to enable Git Partial Clone support?

We are evaluating GitLab as a self-hosted instance for use in our projects, and have been anticipating Git Partial Clone support for a long time, which is something that seems to finally have made it into GitLab 12.4. However, even though the release notes mention it being an “alpha” feature which has to be enabled on a project basis, I can’t find any setting like this in the project settings! How do I enable this feature?

The linked documentation is badly outdated (a bit ironic for a feature that was just released), and the linked issue doesn’t seem to paint the whole picture. Even going through all the changes in the related merge requests, I can’t find anything adding UI for this setting at all. Only this: https://gitlab.com/gitlab-org/gitlab/merge_requests/16850/diffs?view=inline#6355f4be2e26cb9b11a3a6292692dd06803efaa9_81_82

Can I change this feature flag some other way? I don’t expect this to be a stable feature, I just want to be able to evaluate it in a real workflow.

I think I figured out how to set the feature flag manually through the console. This is how I went about it:

> sudo gitlab-ruby console

irb(main):023:0> Feature.enable(:gitaly_upload_pack_filter, Project.find_by_id(4))
=> nil
irb(main):024:0> Feature.enabled?(:gitaly_upload_pack_filter, Project.find_by_id(4))
=> true

You also need to change the “Maximum push size” setting in the Account and Limit section of the admin area to a value greater than 0.