---
# System prepended metadata

title: Triage meeting 2025-10-08
tags: [triage-meeting, T-lang, minutes]

---

---
title: Triage meeting 2025-10-08
tags: ["T-lang", "triage-meeting", "minutes"]
date: 2025-10-08
discussion: https://rust-lang.zulipchat.com/#narrow/channel/410673-t-lang.2Fmeetings/topic/Triage.20meeting.202025-10-08/
url: https://hackmd.io/dbv-WIreSseeO5H-us4xWQ
---

# T-lang meeting agenda

- Meeting date: 2025-10-08

## Attendance

- People: TC, nikomatsakis, tmandry, Josh, dianne, Jack, Martin, Aapo, Yosh, scottmcm

## Meeting roles

- Driver: TC
- Minutes: TC

## Scheduled meetings

- 2025-10-08: "Design meeting: Review RFC 3848 (Pass pointers to `const` in assembly)" [#347](https://github.com/rust-lang/lang-team/issues/347)

Edit the schedule here: https://github.com/orgs/rust-lang/projects/31/views/7.

## Announcements or custom items

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

### Guest attendee items

TC: For any guests who are present, please note in this section if you're attending for the purposes of any items on (or off) the agenda in particular.

### Moving right along

TC: As we've been doing recently, due to the impressive backlog, I'm going to push the pace a bit.  If it's ever too fast or you need a moment before we move on, please raise a hand and we'll pause.

### Design meeting at 12:30 EST / 09:30 PST / 17:30 CET

TC: Remember that we have a design/planning meeting that starts half an hour after this call ends.

### Next meeting with RfL

We're next meeting with RfL on 2025-10-08 to review the status of RfL project goals.

https://github.com/rust-lang/rfcs/pull/3614

Looking at https://github.com/rust-lang/rfcs/pull/3848

## Nominated RFCs, PRs, and issues

### "Lint regression: `dead_code` ignores `#[allow(dead_code)]` on traits" rust#144060

**Link:** https://github.com/rust-lang/rust/issues/144060

TC: Last week we had talked about this.

Josh; A PR went up in:

https://github.com/rust-lang/rust/pull/144113

TC: One example we considered was this one, which warns in 1.89 but not in 1.88.  Did we find out anything about this?

```rust
#[allow(dead_code)]
trait Foo {
    fn f();
}

impl Foo for u32 {
    fn f() {
        g();
    }
}

fn g() {} //[1.89]~ WARN

fn main() {}
```

Josh: If I'm reading 144113 correctly, I think it may fix this as well.

Niko: The behavior I proposed considered what is public, so I think I'd warn here.

### "Stabilize s390x `vector` target feature and `is_s390x_feature_detected!` macro" rust#145656

**Link:** https://github.com/rust-lang/rust/pull/145656

This is waiting for scottmcm.

### "Stabilize 29 RISC-V target features (`riscv_ratified_v2`)" rust#145948

**Link:** https://github.com/rust-lang/rust/pull/145948

This is waiting for scottmcm.

### "Temporary lifetime extension for blocks" rust#146098

**Link:** https://github.com/rust-lang/rust/pull/146098

TC: The crater runs came back as clean as could be expected.  I'll go ahead and propose FCP.

TC: And this is in FCP.

### "Decide about future of `rustc_legacy_const_generics`" rust#146613

**Link:** https://github.com/rust-lang/rust/issues/146613

Josh: People have made comments that what they really want are compile-time constant arguments.  Our only mechanism for this is `legacy_const_generics`.

If we could mark a parameter (not the whole function) as `const`, the compiler could enforce that it is a compile-time constant, and then you can use that constant inside the function as a constant. For instance, you can use it as an asm *immediate*, or write a `const if` on it.

Niko:

```rust
// Implication: this does not implement the `Fn` trait.
fn foo(const N: usize) {
    let x = [22; N];
    // can also use this in an `asm!` as a constant
}

// becomes

fn foo<const N: usize>() {
    ...    
}

// and `foo(22)` becomes `foo::<22>()`

// ...but you can't do this in any other way
```

We should get more feedback from compiler folks on what the issue is with legacy const generics and why it needs to be a different kind of const. We should also get feeback on the above sketch to see if it has the same problems, or different problems.

### "Allow passing `expr` metavariable to `cfg`" rust#146961

**Link:** https://github.com/rust-lang/rust/pull/146961

tmandry: Petrochenkov seems to think this is a special case of something he wants to do anyway.

Josh: It seems, in principle, that we could allow the macro fragments in any position -- that's what we'd do if we treated them exclusively as tokens.  The limitation, as I understand, relates to compile-time performance.  I'll propose FCP.

TC, tmandry: +1.

TC: It's in FCP.

Niko: Why would you not want this?  It's hard to think of a good reason not to do this.

Josh: In theory, if you wanted to build a "correct by construction" macro system, maybe you wouldn't want this, but this isn't what we have anyway.

### "FCW for repr(C) enums whose discriminant values do not fit into a c_int" rust#147017

**Link:** https://github.com/rust-lang/rust/pull/147017

(Discussion, mostly reviewing what RalfJ had said.)

TC: This is now in FCP.

### "Move CoercePointee to core::ops" rust#147068

**Link:** https://github.com/rust-lang/rust/pull/147068

tmandry: (Gives the background.)

Josh: We talked about this in the libs-api call yesterday, and we found this confusing.  The comment at the top of `ops` suggests that it's for overloaded operators, which this isn't.

### "Add warn-by-default lint for visibility on `const _` declarations" rust#147136

**Link:** https://github.com/rust-lang/rust/pull/147136

### "unused_must_use: Don't warn on `Result<(), Uninhabited>` or `ControlFlow<Uninhabited, ()>`" rust#147382

**Link:** https://github.com/rust-lang/rust/pull/147382

### "RFC: Allow cfg-attributes on elements of tuple type declarations" rfcs#3532

**Link:** https://github.com/rust-lang/rfcs/pull/3532

### "RFC: `#[export_visibility = ...]` attribute" rfcs#3834

**Link:** https://github.com/rust-lang/rfcs/pull/3834

### "`dangerous_implicit_autorefs` suggestion is wrong" rust#140721

**Link:** https://github.com/rust-lang/rust/issues/140721

### "`rustc_const_eval`: respect `target.min_global_align`" rust#142198

**Link:** https://github.com/rust-lang/rust/pull/142198

### "error out when `repr(align)` exceeds COFF limit" rust#142638

**Link:** https://github.com/rust-lang/rust/pull/142638

### "Tracking Issue for `darwin_objc`" rust#145496

**Link:** https://github.com/rust-lang/rust/issues/145496

### "Tracking Issue for Reborrow trait lang experiment" rust#145612

**Link:** https://github.com/rust-lang/rust/issues/145612

### "Uplifts and extends `clippy::needless-maybe-sized` into rustc" rust#145924

**Link:** https://github.com/rust-lang/rust/pull/145924

### "compiler and language documentation disagree on lifetime extension for array expressions" rust#146092

**Link:** https://github.com/rust-lang/rust/issues/146092

### "Add a new lint `UNCONSTRUCTABLE_PUB_STRUCT` to detect unconstructable public structs" rust#146440

**Link:** https://github.com/rust-lang/rust/pull/146440

### "Add lint about redefining runtime symbols" rust#146505

**Link:** https://github.com/rust-lang/rust/pull/146505

### "Not linting irrefutable_let_patterns on let chains" rust#146832

**Link:** https://github.com/rust-lang/rust/pull/146832

### "Extend format_args implicit arguments to allow field access" rfcs#3626

**Link:** https://github.com/rust-lang/rfcs/pull/3626

### "RFC: cfg_target_version" rfcs#3750

**Link:** https://github.com/rust-lang/rfcs/pull/3750

### "repr(ordered_fields)" rfcs#3845

**Link:** https://github.com/rust-lang/rfcs/pull/3845

### "Match guard can both move and static-promote a single constant" rust#145237

**Link:** https://github.com/rust-lang/rust/issues/145237

### "`ref` patterns can const-promote a single constant more than once" rust#145555

**Link:** https://github.com/rust-lang/rust/issues/145555

### "Tracking Issue for enum access in offset_of" rust#120141

**Link:** https://github.com/rust-lang/rust/issues/120141

### "Stabilize the `breakpoint` function" rust#142325

**Link:** https://github.com/rust-lang/rust/pull/142325
