Stream: t-compiler/wg-nll

Topic: weekly meeting October 23


nikomatsakis (Oct 23 2018 at 19:28, on Zulip):

Good afternoon @WG-compiler-nll — sync meeting in a few minutes

nikomatsakis (Oct 23 2018 at 19:30, on Zulip):

Triage document

pnkfelix (Oct 23 2018 at 19:33, on Zulip):

hey everyone; sorry, i'm moving a little slow today

pnkfelix (Oct 23 2018 at 19:34, on Zulip):

we've got some recent injections that are probably due to the recent E as T support

nikomatsakis (Oct 23 2018 at 19:34, on Zulip):

did we open an issue on that?

pnkfelix (Oct 23 2018 at 19:34, on Zulip):

there's at least one

pnkfelix (Oct 23 2018 at 19:35, on Zulip):

but e.g. https://github.com/rust-lang/rust/issues/55241 is ... another?

nikomatsakis (Oct 23 2018 at 19:35, on Zulip):

maybe what I really meant is

nikomatsakis (Oct 23 2018 at 19:35, on Zulip):

should we add those to the milestone

nikomatsakis (Oct 23 2018 at 19:35, on Zulip):

@RalfJ pointed out a possible fix over in #t-compiler

pnkfelix (Oct 23 2018 at 19:35, on Zulip):

so the ICE's aren't mitigated

nikomatsakis (Oct 23 2018 at 19:36, on Zulip):

in this topic — but perhaps I misunderstood

pnkfelix (Oct 23 2018 at 19:36, on Zulip):

oh I hadn't seen @RalfJ's note

pnkfelix (Oct 23 2018 at 19:36, on Zulip):

/me was literally lying down five minutes ago

nikomatsakis (Oct 23 2018 at 19:36, on Zulip):

I can take a look at fixing that this afternoon perhaps

pnkfelix (Oct 23 2018 at 19:37, on Zulip):

anyway

pnkfelix (Oct 23 2018 at 19:37, on Zulip):

my suspicion is that the ICE's dont block the release

pnkfelix (Oct 23 2018 at 19:38, on Zulip):

but they should be targetted for backports to beta if they don't get in before the rollover

pnkfelix (Oct 23 2018 at 19:38, on Zulip):

(has the rollover from nightly to beta already happened?)

pnkfelix (Oct 23 2018 at 19:38, on Zulip):

that's tomorrow, right?

nikomatsakis (Oct 23 2018 at 19:38, on Zulip):

probably

nikomatsakis (Oct 23 2018 at 19:38, on Zulip):

FWIW meeting is kinda late, beta/stable promotion needs to happen Wednesday at the absolute latest

nikomatsakis (Oct 23 2018 at 19:38, on Zulip):

that's what @simulacrum said earlier

nikomatsakis (Oct 23 2018 at 19:38, on Zulip):

I don't 100% know what means

nikomatsakis (Oct 23 2018 at 19:39, on Zulip):

should we remove that from the milestone, then, and move to the "release" milestone?

pnkfelix (Oct 23 2018 at 19:39, on Zulip):

"meeting is kinda late" ?

nikomatsakis (Oct 23 2018 at 19:39, on Zulip):

anyway, we're kind of in the weeds a bit here :)

pnkfelix (Oct 23 2018 at 19:39, on Zulip):

this meeting is "kinda late"?

nikomatsakis (Oct 23 2018 at 19:39, on Zulip):

oh, no, that was referreing to something else

nikomatsakis (Oct 23 2018 at 19:39, on Zulip):

the "rust release" mtg I think

pnkfelix (Oct 23 2018 at 19:39, on Zulip):

oh okay

nikomatsakis (Oct 23 2018 at 19:39, on Zulip):

so @pnkfelix and I had been talking about using this meeting to talk "post NLL shipping" plans

nikomatsakis (Oct 23 2018 at 19:40, on Zulip):

but I will say that reviewing the list of work makes me realize there's still plenty of little things to handle ;)

nikomatsakis (Oct 23 2018 at 19:40, on Zulip):

but probably it's good to talk about that anyway

nikomatsakis (Oct 23 2018 at 19:40, on Zulip):

/me hopes https://github.com/rust-lang/rust/pull/55229 will land dang it

pnkfelix (Oct 23 2018 at 19:40, on Zulip):

right. but I'll say up front that my incination was "we're pretty close to being 'done' with NLL as an initial product"

nikomatsakis (Oct 23 2018 at 19:40, on Zulip):

yep, I agree

pnkfelix (Oct 23 2018 at 19:40, on Zulip):

and so I wasn't sure whether we needed this standing meeting as it currently stands

nikomatsakis (Oct 23 2018 at 19:41, on Zulip):

(who's here today, btw?)

nikomatsakis (Oct 23 2018 at 19:41, on Zulip):

looks like @Matthew Jasper and @davidtwco

nikomatsakis (Oct 23 2018 at 19:41, on Zulip):

(from paper doc)

pnkfelix (Oct 23 2018 at 19:41, on Zulip):

(and from the waves above)

davidtwco (Oct 23 2018 at 19:41, on Zulip):

:wave:

nikomatsakis (Oct 23 2018 at 19:42, on Zulip):

I left some notes in the paper doc (e.g., here)

nikomatsakis (Oct 23 2018 at 19:42, on Zulip):

just kind of "brain dumping"

nikomatsakis (Oct 23 2018 at 19:43, on Zulip):

it might be worth looking at the A-nll bugs though; it seems to me that when it comes to diagnostics we are basically at the "good enough" category, though I still think it'd be great to have a renewed push around simplifying our vocabulary etc, but I might like to get a bit of experience first

pnkfelix (Oct 23 2018 at 19:43, on Zulip):

yeah I still need to do the .stderr review

nikomatsakis (Oct 23 2018 at 19:44, on Zulip):

notably we still have 19 bugs tagged to the final release in 6 weeks

pnkfelix (Oct 23 2018 at 19:44, on Zulip):

a bunch of those are NLL-fixed-by-NLL though

pnkfelix (Oct 23 2018 at 19:44, on Zulip):

well, two

pnkfelix (Oct 23 2018 at 19:45, on Zulip):

the NLL-deferred might be more worrisome

nikomatsakis (Oct 23 2018 at 19:45, on Zulip):

8 are diagnostics

nikomatsakis (Oct 23 2018 at 19:45, on Zulip):

7 are soundness

nikomatsakis (Oct 23 2018 at 19:45, on Zulip):

basically all user type annot

nikomatsakis (Oct 23 2018 at 19:45, on Zulip):

some ICEs

nikomatsakis (Oct 23 2018 at 19:46, on Zulip):

and 3 NLL-deferred issues :)

davidtwco (Oct 23 2018 at 19:47, on Zulip):

That same search without NLL-fixed-by-NLL.

nikomatsakis (Oct 23 2018 at 19:48, on Zulip):

anyway I think all that this means is that there is (sadly) still some work to do on user-type annotations post RC2

nikomatsakis (Oct 23 2018 at 19:48, on Zulip):

this brings up that question I raised of whether we expect to backport those things

nikomatsakis (Oct 23 2018 at 19:48, on Zulip):

plus I imagine there'll be more ICEs

simulacrum (Oct 23 2018 at 19:48, on Zulip):

@nikomatsakis @pnkfelix FWIW nightly/beta promotion is early next week, that was specifically referencing anything that needs to be in current beta (i.e., Thursday's stable)

nikomatsakis (Oct 23 2018 at 19:48, on Zulip):

@simulacrum I see

simulacrum (Oct 23 2018 at 19:49, on Zulip):

Which was I think a non-NLL thing that I was referencing

simulacrum (Oct 23 2018 at 19:49, on Zulip):

Is there an NLL thing that I should be aware of?

nikomatsakis (Oct 23 2018 at 19:49, on Zulip):

not related to current stable

nikomatsakis (Oct 23 2018 at 19:49, on Zulip):

we are trying to close out all the RC2 blockers

simulacrum (Oct 23 2018 at 19:49, on Zulip):

okay, sounds good

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

really right now we've just got one

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

which is being tested by bors right now

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

however

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

there are some ICEs that have been cropping up

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

so those might be "nice to haves"

nikomatsakis (Oct 23 2018 at 19:50, on Zulip):

once we have a fix

pnkfelix (Oct 23 2018 at 19:50, on Zulip):

wait nightly/beta promotion is next week ... based on, whatever state nightly is in at that time next week?

simulacrum (Oct 23 2018 at 19:51, on Zulip):

well, it was supposed to be today

pnkfelix (Oct 23 2018 at 19:51, on Zulip):

as in, the October 25th deadline is ... very soft indeed?

davidtwco (Oct 23 2018 at 19:51, on Zulip):

I've not had a chance to pickup a new issue yet - if there's anything that has a priority that you think I could handle I can dump some time into it over the next few days.

simulacrum (Oct 23 2018 at 19:51, on Zulip):

Yes, because it's RC2

simulacrum (Oct 23 2018 at 19:51, on Zulip):

The next milestone is not debatable/modifiable

nikomatsakis (Oct 23 2018 at 19:51, on Zulip):

@davidtwco maybe one of these ICEs

pnkfelix (Oct 23 2018 at 19:51, on Zulip):

i see, so the rollover date for RC2 is slipping a few days then?

pnkfelix (Oct 23 2018 at 19:52, on Zulip):

just trying to make sure I understand

simulacrum (Oct 23 2018 at 19:52, on Zulip):

Yes, because I think there's NLL work and a few other things that want to be in that beta so we'll just wait instead of backporting

davidtwco (Oct 23 2018 at 19:52, on Zulip):

All three of the I-ICE issues are assigned to you or @pnkfelix - are there others that aren't tagged like that?

nikomatsakis (Oct 23 2018 at 19:52, on Zulip):

I don't know of one, we could maybe unassign

simulacrum (Oct 23 2018 at 19:52, on Zulip):

(I think it makes the release slightly smoother too, in some sense -- less things that need to happen this week)

simulacrum (Oct 23 2018 at 19:54, on Zulip):

Just to make sure NLL has no work that needs to land in current stable, right?

pnkfelix (Oct 23 2018 at 19:54, on Zulip):

I believe that is the case, yes (that there is no NLL work that needs to land in the current stable)

simulacrum (Oct 23 2018 at 19:54, on Zulip):

Okay -- if not, please ping me so I can be aware of it before the release :)

pnkfelix (Oct 23 2018 at 19:55, on Zulip):

I don't think we even have anything that needs to lands in the current beta, either ... right?

nikomatsakis (Oct 23 2018 at 19:55, on Zulip):

Hmm @davidtwco these ICEs don't all look the same; some of the ones in #55241 may be fixed by my PR

pnkfelix (Oct 23 2018 at 19:56, on Zulip):

we basically were deciding about whether to try to force some stuff in, or plan on backports, or just let certain subtle things ship in a buggy state initially

nikomatsakis (Oct 23 2018 at 19:56, on Zulip):

@pnkfelix well I had #55229 as a blocker, since it's ready and fixes various ICEs and unsoundnesses

nikomatsakis (Oct 23 2018 at 19:56, on Zulip):

but if push came to shove...

nikomatsakis (Oct 23 2018 at 19:56, on Zulip):

anyway, it should hopefully land very soon

nikomatsakis (Oct 23 2018 at 19:56, on Zulip):

er, sorry, wrong link (fixed)

pnkfelix (Oct 23 2018 at 19:57, on Zulip):

right, but that isn't targeting current beta? Just nightly?

pnkfelix (Oct 23 2018 at 19:58, on Zulip):

I guess I may not be talking clearly about "current beta" vs "next beta' ?

nikomatsakis (Oct 23 2018 at 19:58, on Zulip):

/me confused

nikomatsakis (Oct 23 2018 at 19:58, on Zulip):

sorry I misunderstood you I guess

pnkfelix (Oct 23 2018 at 19:58, on Zulip):

I was just reacting to @simulacrum 's Q "Just to make sure NLL has no work that needs to land in current stable, right?"

nikomatsakis (Oct 23 2018 at 19:58, on Zulip):

right, I think your answer is correct

pnkfelix (Oct 23 2018 at 19:59, on Zulip):

anyway it certainly sounds like #55229 will land in time

pnkfelix (Oct 23 2018 at 19:59, on Zulip):

Holy crow its been 29minutes and we haven't even mentioned what I thought was going to be the main topic of the meeting

nikomatsakis (Oct 23 2018 at 19:59, on Zulip):

lol

davidtwco (Oct 23 2018 at 19:59, on Zulip):

If you want to pick something suitable and assign me it then I'll take a look at that.

davidtwco (Oct 23 2018 at 20:00, on Zulip):

I'll also pick up random diagnostic issues throughout the week if I have time.

nikomatsakis (Oct 23 2018 at 20:00, on Zulip):

@pnkfelix which is the &'staticissue we were talking about again...?

Matthew Jasper (Oct 23 2018 at 20:00, on Zulip):

#55288

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

right

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

/me puts it on the milestone

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

so, @davidtwco, I think we should investigate that one https://github.com/rust-lang/rust/issues/55288 :)

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

might require a bit of context

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

but we can chat about it over in another topic

nikomatsakis (Oct 23 2018 at 20:01, on Zulip):

I just assigned you tho

davidtwco (Oct 23 2018 at 20:02, on Zulip):

Sounds good.

nikomatsakis (Oct 23 2018 at 20:02, on Zulip):

the topic that @pnkfelix and I had intended to cover was sort of the "post shipping plans"... you can see I left some notes about possible directions we can go ...

nikomatsakis (Oct 23 2018 at 20:02, on Zulip):

@pnkfelix and I were chatting this morning and in particular debating about whether to push more on polonius or wait until we've "cleaned up" the existing codebase more

nikomatsakis (Oct 23 2018 at 20:02, on Zulip):

since right now it is kind of a mess — for example, we have two borrow checkers and two region checkers :)

nikomatsakis (Oct 23 2018 at 20:03, on Zulip):

(3 if you count polonius in its current state...)

Matthew Jasper (Oct 23 2018 at 20:03, on Zulip):

Double the safety

nikomatsakis (Oct 23 2018 at 20:03, on Zulip):

we sort of surprised ourselves by finding that it seemed like it made sense to push on polonius — basically because it shouldn't impede the other stuff, hopefully, and that stuff kind of has to bake before we can do much simplification

nikomatsakis (Oct 23 2018 at 20:04, on Zulip):

I think that over the next N weeks though a lot depends on how much work we wind up having to do getting NLL formally shipped

nikomatsakis (Oct 23 2018 at 20:06, on Zulip):

Anyway, I guess we'll talk about it more next time. I hope to put in some time bringing polonius back in cache this week, though I've said that before. I'd like to at least start documenting poloinius in rustc-guide and decide whether that case that was a discrepancy between opt and naive was indeed a bug

nikomatsakis (Oct 23 2018 at 20:06, on Zulip):

it occurs to me btw @pnkfelix that this is another work item — documenting

nikomatsakis (Oct 23 2018 at 20:06, on Zulip):

e.g., rustc-guide, but also rust reference etc

pnkfelix (Oct 23 2018 at 20:06, on Zulip):

right

Matthew Jasper (Oct 23 2018 at 20:06, on Zulip):

I hope to get to that before too long

Matthew Jasper (Oct 23 2018 at 20:07, on Zulip):

for the reference at least

nikomatsakis (Oct 23 2018 at 20:07, on Zulip):

to what specifically? ah

nikomatsakis (Oct 23 2018 at 20:08, on Zulip):

well I guess we can talk about it more next week

nikomatsakis (Oct 23 2018 at 20:08, on Zulip):

besides that ICE, I think the top priority should be the user-type-annot bugs

nikomatsakis (Oct 23 2018 at 20:08, on Zulip):

not sure how many of those are really left

Matthew Jasper (Oct 23 2018 at 20:09, on Zulip):

There are open PRs for the two major cases

pnkfelix (Oct 23 2018 at 20:09, on Zulip):

yeah we've got some PR's to land

Matthew Jasper (Oct 23 2018 at 20:09, on Zulip):

The rest appear to be unfortunate edge cases

pnkfelix (Oct 23 2018 at 20:10, on Zulip):

and normalization related bugs

pnkfelix (Oct 23 2018 at 20:10, on Zulip):

not sure if that's "edge case" or not

nikomatsakis (Oct 23 2018 at 20:12, on Zulip):

yeah I want to dig into that one more...

Santiago Pastorino (Oct 23 2018 at 21:17, on Zulip):

sorry I couldn’t participate today, travelling to Mexico

Santiago Pastorino (Oct 23 2018 at 21:18, on Zulip):

gonna read the log tomorrow

Last update: Nov 21 2019 at 13:20UTC