Could you point me at an example revision to see how this looks?

It's sort of like:

• Evan creates a new branch off master/remote.
• I check out branch/remote
• <Code> <Review> <Land on Branch/Remote>
• Repeat
• Merge branch into master.

I can't easily find an example, think its been about 18 months since we last did a feature branch.

Hmm, but that's not quite the same thing as what I'm asking (I think) -- in my scenario a pair of authors are adding commits to a branch off master (imagine it's a refactor and we're fixing different tests), and the stack of commits is reviewed in one PR. I know I can do this today by just creating a remote branch, collaborating with someone on it, and doing no code review until all the commits land (at which time one of us creates the Differential revision).

However, there are a few situations where author1 adds a new feature; while that is in review, author2 wants to build on top of it. They realize while doing so that the new feature could use a tweak, and want to contribute back to that revision. This process is awkward in the arc patch workflow, and much more convenient when there is a remote branch to check out.

Personally, I think it's maybe easier to do review along the way, but you can go the other route where you just both git push to the remote branch, then review run arc diff when you want to merge it into master.

Yes, that works if you decide to collaborate ahead of time. If you decide to "stack" on top of a revision under review, you have to either

• arc patch (but how do you handle it when the revision is updated?)
• Ask the author to push a remote branch.

Making it possible to synchronize an arc patch branch with the revision would at least make it possible to stack on top of it without being able to contribute to it. Has that been considered?

Oh, yeah, maybe need @avivey or @epriestley for those questions. Over my pay grade.

I have read https://secure.phabricator.com/phame/post/view/766/write_review_merge_publish_phabricator_review_workflow/ , and it briefly addresses this:

Phabricator allows you to fetch changes with arc patch, which may be suitable. But there's also no reason you can't push changes somewhere in addition to going through the Phabricator flow, although you may have to change some settings.

The "a bunch of developers do stuff together and then kind of review it together" flow is so informal and ad-hoc that I think it doesn't really make sense to try to put tooling on top of it. If that's what makes sense for your project, just go with whatever works, man. As above, there's no reason you can't do this alongside the Phabricator review workflow.

In our environment the common case is a Phabricator-like workflow; I'm just looking to see if there's a way to make the less-common (but still not infrequent) collaboration/stacking flow easier.

I think that if you use Dependencies in revisions, arc patch will pull the dependencies as well as separate commits; Then you can do something like this:

• arc patch the revision you're about the update
• make all the changes
• git commit --amend, to have all these changes go in the same commit
• arc diff HEAD~ to only take these changes to update the diff
• remove local branch
• repeat

This is somewhat complicated flow, but it lets you build the whole stack in parallel, without committing to anything.

I don't think there's any sane way to update a branch that was already obtained from arc patch; You can do some tricks with arc-patching again and interactive rebasing, but that will up being complicated.