---
title: Triage meeting 2023-04-11
tags: triage-meeting
---

# T-lang meeting agenda

* Meeting date: 2023-04-11

## Attendance

* Team members: pnkfelix, scottmcm, cramertj, tmandry
* Others: y86-dev, Lokathor, dtolnay

## Meeting roles

* Action item scribe: tmandry
* Note-taker: tmandry

## Scheduled meetings
- "The #[diagnostic] attribute namespace" [lang-team#204](https://github.com/rust-lang/lang-team/issues/204)

tmandry: Intent to look at the RFC and unblock, no separate doc

pnkfelix: Pinged weiznich and estebank

## Announcements or custom items

(Meeting attendees, feel free to add items here!)

- Confusion about RFC process, Zulip thread: <https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/.E2.9C.94.20Do.20new.20RFCs.20need.20.20to.20be.20nominated.20to.20be.20in.20a.20triage.20mee.2E.2E.2E/near/348305124>.

## Action item review

* [Action items list](https://hackmd.io/gstfhtXYTHa3Jv-P_2RK7A)

## Pending lang team project proposals

None.

## PRs on the lang-team repo

None.

## RFCs waiting to be merged
### "RFC: result_ffi_guarantees" rfcs#3391

**Link:** https://github.com/rust-lang/rfcs/pull/3391

pnkfelix: dtolnay [commented](https://github.com/rust-lang/rfcs/pull/3391#issuecomment-1498066399), what's the status of that? Lokathor?

dtolnay: No response needed.

Lokathor: We have to make sure that all ABIs follow the proposal including weird ones

## Proposed FCPs

**Check your boxes!**
### "unsafe attributes" rfcs#3325

- **Link:** https://github.com/rust-lang/rfcs/pull/3325
- [**Tracking Comment**](https://github.com/rust-lang/rfcs/pull/3325#issuecomment-1396911253):
> Team member @joshtriplett has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @joshtriplett
> * [x] @nikomatsakis
> * [x] @pnkfelix
> * [x] @scottmcm
> * [x] @tmandry
>
> Concerns:
>
> * ~~change-syntax-to-drop-parentheses~~ resolved by https://github.com/rust-lang/rfcs/pull/3325#issuecomment-1458714974
> * ~~maybe-make-this-part-of-next-edition~~ resolved by https://github.com/rust-lang/rfcs/pull/3325#issuecomment-1458690311
> * syntax-not-ideal (https://github.com/rust-lang/rfcs/pull/3325#issuecomment-1458714974)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rfcs/pull/3325#issuecomment-1396911218):
> @rfcbot merge

We've skipped over this several times since team members weren't here to have the bikeshed. Doing that again.

### "RFC: UTF-8 characters and escape codes in (byte) string literals" rfcs#3349

- **Link:** https://github.com/rust-lang/rfcs/pull/3349
- [**Tracking Comment**](https://github.com/rust-lang/rfcs/pull/3349#issuecomment-1396747916):
> Team member @joshtriplett has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @joshtriplett
> * [x] @nikomatsakis
> * [ ] @pnkfelix
> * [ ] @scottmcm
> * [ ] @tmandry
>
> Concerns:
>
> * raw-byte-strings-with-unicode (https://github.com/rust-lang/rfcs/pull/3349#issuecomment-1396747889)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rfcs/pull/3349#issuecomment-1396747889):
> I do think we should permit `br"¥¥¥"`, but I don't think we should make any of the other changes proposed in that table, for the reasons @m-ou-se stated.
>
> I'm going to go ahead and propose FCP for this. This does *not* preclude making further changes to how this information is presented.
>
> @rfcbot merge
>
> @rfcbot concern raw-byte-strings-with-unicode

tmandry: nnethercote had a concern

pnkfelix: Mara responded positively saying she would update, but hasn't had time yet

pnkfelix: I'll file a formal concern to track.

### "Tracking issue for RFC 2515, "Permit impl Trait in type aliases"" rust#63063

- **Link:** https://github.com/rust-lang/rust/issues/63063
- [**Tracking Comment**](https://github.com/rust-lang/rust/issues/63063#issuecomment-1360043090):
> Team member @nikomatsakis has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @cramertj
> * [x] @joshtriplett
> * [x] @nikomatsakis
> * [ ] @pnkfelix
> * [ ] @scottmcm
>
> Concerns:
>
> * ~~~~ resolved by https://github.com/rust-lang/rust/issues/63063#issuecomment-1361432898
> * docs (https://github.com/rust-lang/rust/issues/63063#issuecomment-1364525286)
> * function-defining-uses (https://github.com/rust-lang/rust/issues/63063#issuecomment-1385946789)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/issues/63063#issuecomment-1360043060):
> @rfcbot fcp merge
>
> This has been a long-time coming. Let's Do This!
>
> [Stabilization report in this comment.](https://github.com/rust-lang/rust/issues/63063#issuecomment-1354392317)

(missed a bunch of things)

pnkfelix: The last comment is interesting

tmandry: Maybe this `#[defines]` thing needs a new RFC

cramertj: ...yeah I agree

cramertj: If we go with `#[defines]` it wouldn't be compatible with restricting the set of possible defining uses further, later on

cramertj: At one point the proposal allowed unifying across partially defining uses (may have been torn out)

tmandry: We could still do a maximally conservative thing

cramertj: That would be only in return position and only with an attribute

pnkfelix: Are we ever going to want defining uses to come from inside a function (not in the signature)? If so we definitely need `#[defines]`. Otherwise I'd prefer to live in a world without that.

cramertj: Wait where does the attribute go?

tmandry: On the function

cramertj/pnkfelix: Oh that's surprising

cramertj: This seems subtle enough to need an RFC

cramertj: You could do syntactic analysis to find defining uses without compiling the whole function and doing typeck

scottmcm: Hypothetically we could avoid parsing function bodies

cramertj: Like I could write a regex for this

tmandry: Need name resolution

cramertj: Or you could look at all defining uses anywhere and then see if it resolves

scottmcm: Find myself agreeing with the notion that this is subtle enough that it warrants an RFC. Could scope discussion not to whether we want this feature or various syntax changes, but just the defining use conversation.

tmandry: Can we make a comment?

pnkfelix: I know we just said the maximally conservative position is to require `#[defines]`, but is there any chance we could back stabilizing the "sugary cases" (fns/impls/consts/statics) in [this comment](https://github.com/rust-lang/rust/issues/107645#issuecomment-1469972682)?

cramertj: Appearing in one of those signatures wouldn't be the same thing as having `#[defines]`, so it's not really backwards compatible

pnkfelix: Not happy with heavily delaying it but also don't see how to move forward

cramertj: In the past we've had RFCs like this where we were about to stabilize something that'd been in process for awhile

pnkfelix: I think we can let oli continue working on the attribute since enough of the lang team is interested in it.

pnkfelix to write a comment

### "Tracking Issue for `debugger_visualizer`" rust#95939

- **Link:** https://github.com/rust-lang/rust/issues/95939
- [**Tracking Comment**](https://github.com/rust-lang/rust/issues/95939#issuecomment-1496371829):
> Team member @wesleywiser has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [ ] @Aaron1011
> * [x] @cjgillot
> * [x] @davidtwco
> * [x] @eddyb
> * [ ] @estebank
> * [x] @joshtriplett
> * [x] @lcnr
> * [x] @matthewjasper
> * [x] @michaelwoerister
> * [ ] @nagisa
> * [x] @nikomatsakis
> * [x] @oli-obk
> * [x] @petrochenkov
> * [ ] @pnkfelix
> * [x] @scottmcm
> * [ ] @tmandry
> * [x] @wesleywiser
>
> No concerns currently listed.
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/issues/95939#issuecomment-1496371801):
> I think this is ready for stabilization.
>
> @gibbyfree wrote a [stabilization report](https://github.com/rust-lang/rust/issues/95939#issuecomment-1456938444) and the associated PR is #108668.
>
> @rfcbot fcp merge

### "Stabilise inline_const" rust#104087

- **Link:** https://github.com/rust-lang/rust/pull/104087
- [**Tracking Comment**](https://github.com/rust-lang/rust/pull/104087#issuecomment-1350231887):
> Team member @scottmcm has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @cramertj
> * [x] @joshtriplett
> * [x] @nikomatsakis
> * [ ] @pnkfelix
> * [x] @scottmcm
>
> Concerns:
>
> * ~~expectations-around-panics-in-inline-const~~ resolved by https://github.com/rust-lang/rust/pull/104087#issuecomment-1449080210
> * optimization-dependent-errors (https://github.com/rust-lang/rust/pull/104087#issuecomment-1449080210)
> * ~~post-monomorphization-errors~~ resolved by https://github.com/rust-lang/rust/pull/104087#issuecomment-1448730779
> * should-unused-code-cause-errors (https://github.com/rust-lang/rust/pull/104087#issuecomment-1410921524)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/pull/104087#issuecomment-1350231871):
> Restarting the FCP from https://github.com/rust-lang/rust/pull/104087#issuecomment-1315946122
>
> @rfcbot fcp merge

### "Stabilize `anonymous_lifetime_in_impl_trait`" rust#107378

- **Link:** https://github.com/rust-lang/rust/pull/107378
- [**Tracking Comment**](https://github.com/rust-lang/rust/pull/107378#issuecomment-1430287200):
> Team member @joshtriplett has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @joshtriplett
> * [ ] @nikomatsakis
> * [ ] @pnkfelix
> * [ ] @scottmcm
> * [ ] @tmandry
>
> Concerns:
>
> * elaborate-cases-and-future-directions (https://github.com/rust-lang/rust/pull/107378#issuecomment-1480280524)
> * why-not-higher-rank (https://github.com/rust-lang/rust/pull/107378#issuecomment-1480280524)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/pull/107378#issuecomment-1430287177):
> We discussed this in today's @rust-lang/lang meeting, and we think this is ready for an FCP to merge:
>
> @rfcbot merge
>
> We'd also like to make sure that future work on type-alias impl Trait (TAIT) doesn't automatically assume anonymous lifetimes will work there, and thinks carefully about how or if that should work.

### "TAIT defining scope options" rust#107645

- **Link:** https://github.com/rust-lang/rust/issues/107645
- [**Tracking Comment**](https://github.com/rust-lang/rust/issues/107645#issuecomment-1468728438):
> Team member @nikomatsakis has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @joshtriplett
> * [x] @nikomatsakis
> * [x] @pnkfelix
> * [x] @scottmcm
> * [x] @tmandry
>
> Concerns:
>
> * explicit-alternative (https://github.com/rust-lang/rust/issues/107645#issuecomment-1469979788)
> * why-not-just-the-return-type (https://github.com/rust-lang/rust/issues/107645#issuecomment-1468796621)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/issues/107645#issuecomment-1468728409):
> @rfcbot fcp merge
>
> I propose that we accept https://github.com/rust-lang/rust/pull/107809. It implements a conservative path forward. Basically any function that constraints a TAIT but doesn't list the TAIT in its arguments/return type is a hard error, giving us room to change the behavior in the future.
>
> ### Final behavior as I understand it
>
> * A TAIT has a *defining scope* that corresponds to the enclosing module or item.
> * A *defining use* for a TAIT is any item that (a) is within the defining scope and (b) contains a function that lists the TAIT in the argument or return types, either before or after normalization (*see edge case below).
> * Within the defining scope, an item is called *constraining* if it puts constraints on the value of the TAIT. i.e., for the item to type check, the hidden type of the TAIT must have a particular value. This could occur because of a `let` (e.g., `let x: TAIT = 22_u32`), a return (e.g., `return 22_u32` in a function whose return type is `TAIT`), or in other ways.
> * Any *constraining* item within the defining scope that is not a *defining use* is a hard error. This means we can later opt to allow such a use; or to allow it with an annotation of some kind; or to make other such changes.
> * All *defining uses* must fully infer the hidden type of the TAIT and must infer the same type for the TAIT.
> * WIthin the defining scope, TAITs must always be given generic arguments (e.g., `fn foo<T>() -> TAIT<T>` and not `fn foo() -> TAIT<u32>`). This ensures inference is tractable and well-defined.
>
> ### Current bugs and limitations (forwards compatible to change)
>
> * Within the defining scope, attempts to check whether `TAIT` implements an auto-trait will yield a cycle error unless the auto-trait is listed in the TAIT's bounds. This is suboptimal, but the ideal fix is unclear.
> * A function that has an argument which is an associated type referencing a TAIT (e.g. `<TAIT as SomeTrait>::SomeItem`) ought to be considered a *defining use*. However, in the compiler today, if that associated type can be normalized, and the normalized form does not reference the TAIT, the function is not. This can only cause more errors.
>
> @rustbot labels -I-lang-nominated

### "Make late_bound_lifetime_arguments a hard error." rust#108782

- **Link:** https://github.com/rust-lang/rust/pull/108782
- [**Tracking Comment**](https://github.com/rust-lang/rust/pull/108782#issuecomment-1468627626):
> Team member @nikomatsakis has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [ ] @joshtriplett
> * [x] @nikomatsakis
> * [ ] @pnkfelix
> * [x] @scottmcm
> * [ ] @tmandry
>
> Concerns:
>
> * types-team-input (https://github.com/rust-lang/rust/pull/108782#issuecomment-1477170467)
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/pull/108782#issuecomment-1468627594):
> @rfcbot fcp merge
>
> Discussed in a (minimally attended) lang-team triage meeting and we are in favor of moving forward with this.
>

### "Stabilize raw-dylib, link_ordinal, import_name_type and -Cdlltool" rust#109677

- **Link:** https://github.com/rust-lang/rust/pull/109677
- [**Tracking Comment**](https://github.com/rust-lang/rust/pull/109677#issuecomment-1491574659):
> Team member @michaelwoerister has proposed to merge this. The next step is review by the rest of the tagged team members:
>
> * [x] @Aaron1011
> * [x] @cjgillot
> * [x] @davidtwco
> * [x] @eddyb
> * [ ] @estebank
> * [ ] @joshtriplett
> * [x] @lcnr
> * [x] @matthewjasper
> * [x] @michaelwoerister
> * [ ] @nagisa
> * [x] @nikomatsakis
> * [x] @oli-obk
> * [x] @petrochenkov
> * [ ] @pnkfelix
> * [ ] @scottmcm
> * [x] @tmandry
> * [x] @wesleywiser
>
> No concerns currently listed.
>
> Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!
>
> cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
> See [this document](https://github.com/rust-lang/rfcbot-rs/blob/master/README.md) for info about what commands tagged team members can give me.
- [**Initiating Comment**](https://github.com/rust-lang/rust/pull/109677#issuecomment-1491574605):
> Thanks, @dpaoliello! Let's start the FCP then. This includes the lang team for final sign off on the `import_name_type` field of the `#[link]` attribute. In https://github.com/rust-lang/rust/pull/100732#issuecomment-1225873457, @joshtriplett gave a general OK for the new key, but let's make it part of an FCP.
>
> @dpaoliello's extensive stabilization report is in the tracking issue at https://github.com/rust-lang/rust/issues/58713#issuecomment-1485826095.
>
> @rfcbot fcp merge
>

## Active FCPs
### "Tracking issue for the #[alloc_error_handler] attribute (for no_std + liballoc)" rust#51540

**Link:** https://github.com/rust-lang/rust/issues/51540

### "Uplift `clippy::{drop,forget}_{ref,copy}` lints" rust#109732

**Link:** https://github.com/rust-lang/rust/pull/109732

## P-critical issues

None.

## Nominated RFCs, PRs and issues discussed this meeting

(none yet, move things from the section below as they are discussed)

### "regression: unaligned references to packed fields are now an error" rust#109745

**Link:** https://github.com/rust-lang/rust/issues/109745

Nomination comment: <https://github.com/rust-lang/rust/issues/109745#issuecomment-1496971041>.

tmandry: This has been a future-incompat lint for awhile

cramertj: And someone in the thread realized that the warning they were ignoring was in fact UB :)

scottmcm: This is deny-by-default

cramertj/scottmcm: And future-incompat and we got it added to the cargo report so it did show up.

cramertj: It's not the same as all future incompat lints by default?

scottmcm: That's what I recall

tmandry: How much time do we have?

cramertj: Realistically we should probably decide today

Lokathor: Some of these crates haven't seen changes for about a year.

tmandry: How long has it been deny-by-default?

Lokathor: A lot of these are bitrot

tmandry: Would love for code to keep working but this is a valid exception

tmandry: Would like more information

cramertj: Tracking issue for future-incompat lint was created in Feb 2021. Original issue for allowing repr(packed) loads was filed in 2015.

Lokathor: The code is already broken

tmandry: I'll leave a comment not to block

## Nominated RFCs, PRs and issues NOT discussed this meeting
### "unsafe attributes" rfcs#3325

**Link:** https://github.com/rust-lang/rfcs/pull/3325

### "RFC: Start working on a Rust specification" rfcs#3355

**Link:** https://github.com/rust-lang/rfcs/pull/3355

### "dyn Trait comparison should not include the vtable pointer" rust#106447

**Link:** https://github.com/rust-lang/rust/issues/106447