In #61182, Bryan has an excellent list of friction around the GitHub PR workflow, including:

A significant fraction of GitHub PRs are abandoned when the author does not respond to Gerrit comments, but the existence of an open PR discourages other contributors from working on the corresponding issue.

One minor thing we could do to shave off some friction is leave a welcome comment in Gerrit after a PR is imported, wherein we:

• ask the PR author to respond to the comment in Gerrit confirming the CL is ready for review, and
• provide some context to the possibly new contributor, including a link to the Review section of the contributing guide

If they respond to the comment, a potential reviewer then knows that the author:

• has a Gerrit account, and
• knows how to reply in Gerrit

To make this suggestion more concrete, I will send a draft CL shortly.

Possible extensions

A modest extension would be to have a reminder comment after a week or so if the author does not reply. This could include some hints around the reply mechanism, including to help with the problem of unpublished Gerrit draft responses.

Another extension would be to automatically abandon the CL and close the PR with an explanatory message if there is no reply after a month or so. This would help with the problem of an open PR discouraging other contributors.

Both of these possible extensions are left as TODOs in the code and possible future issues.