Python 3 cleanups

It’s not clear to me how to best submit this series. For now, I submit the series as one merge request. Feel free to merge parts of it.

I sent a mail to the mailing list, but it doesn’t seem to work currently. Here is a copy of it:

I have a branch with Python 3 cleanups (https://foss.heptapod.net/mercurial/mercurial-devel/-/compare/default...py3-cleanups). It consists of more than 30 changesets already and will grow larger.

Phabricator has a strong focus on single patches. There, I would submit each patch shortly after creating them. Each can be reviewed and approved individually.

On Heptapod, the focus is more on whole merge request. The Wiki page says that review should be done on single changesets, but it seems like only the whole merge request can be approved and merged (in the UI).

If I create a single merge request when the series is finished (which is whenever I don’t feel to continue), it will be very large and hard to review in one pass. Also, it would mean that I would get feedback on the first changesets later, increasing the chance of getting merge conflicts when changing later changesets (in this case, it hopefully wouldn’t be an issue, because the changes are not very complex).

If I create a single merge request and continue to add changesets to it, feedback on the first changesets will possibly be earlier, but CI can temporarily break for newer changesets while I keep working on it.

If I create a merge request for each changeset, it will be many and each merge request will contain the unmerged ancestors. Also, I think it would require that each changeset is in its own topic, which complicates matters when working with them locally.

I could split them in smaller batches, but it’s not clear how large they should be, and it would combine disadvantages of the two other approaches (although less pronounced).

Thoughts?