Re: Opinion poll: Sending an automated email to a thread when it gets added to the commitfest

On Thu, Aug 15, 2024 at 9:33 AM Peter Eisentraut <peter(at)eisentraut(dot)org> wrote:
> But a more serious concern here is that the patches created by the cfbot
> are not canonical. There are various heuristics when they get applied.

It's true that the code required for CFBot to simply apply a patch is
nontrivial. We're accounting for various edge-cases, and soldiering
on, where we deem that it makes sense. I'm referring to those cases
where "git am" won't work perfectly, but we have a pretty good chance
of successfully generating what the patch author intended (I assume
that that's what you meant by "heuristics").

One reason why this works better than might be expected is
because...we then test the result (that's the whole point, of course).
Obviously, if we apply a patch in a way that isn't quite perfectly
clean (according to whatever the "git am" criteria is), but that CFBot
is nevertheless capable of applying, and we then find that the end
result passes all tests, that gives us a fairly strong signal. We can
have high confidence that CFBot has done the right thing at that
point. We can reasonably present the resulting feature branch as a
"known good" usable version of the patch.

Of course you can quibble with this. Fundamentally, a patch file can
never be updated, but we want to apply it on top of a moving target
(as best we can). We're always making some kind of trade-off. I just
don't think that the heuristics that humans might choose to apply are
necessarily much better on average. Humans are bad at routine boring
things, but good at noticing and coping with special cases.

> I would prefer that people work with the actual patches sent by email,
> at least unless they know exactly what they are doing. We don't want to
> create parallel worlds of patches that are like 90% similar but not
> really identical.

There's a reason why tech companies place so much emphasis on offering
a "low friction experience". The aggregate effect on user/consumer
behavior is huge. I'm not saying that this is good or bad (let's not
get into that now); just that it is an empirical fact that people tend
to behave like that. We want more reviewers. Why not try to meet
people where they are a bit more?

I have to admit that I think that I'd be far more likely to quickly
test out a patch if I'm presented with a workflow that makes the setup
as painless as possible. Particularly if I'm all but guaranteed to get
a working Postgres server with the patch applied (which is possible
when I'm building exactly the same feature branch as the one that
passed CI by CFBot). I'm entirely willing to believe that it wouldn't
work that way for you, but I'm confident that a lot of people are in
the same camp as me.

--
Peter Geoghegan