Stream: t-compiler/wg-prioritization/alerts

Topic: I-prioritize #77458 ICE on trying to debug format type

triagebot (Oct 04 2020 at 00:27, on Zulip):

@WG-prioritization/alerts issue #77458 has been requested for prioritization.

Procedure

Joshua Nelson (Oct 04 2020 at 01:16, on Zulip):

P-low IMO, the only people that could run into this are contributors trying to debug things

Joshua Nelson (Oct 04 2020 at 01:16, on Zulip):

you could make an argument this makes it harder to get started in the codebase, but no more so than rustdoc having random ICEs if you call tcx.whatever() on a fake DefId

Camelid (Oct 04 2020 at 01:53, on Zulip):

I requested prioritization because it seems there might be something weird going on that could affect other things

Camelid (Oct 04 2020 at 01:53, on Zulip):

It's not necessarily limited to rustc_middle::ty::Ty, that's just where it was found, correct?

Joshua Nelson (Oct 04 2020 at 01:53, on Zulip):

well in the sense that you can print debug output anywhere, yes

Joshua Nelson (Oct 04 2020 at 01:53, on Zulip):

but debug output is never user-facing

Joshua Nelson (Oct 04 2020 at 01:54, on Zulip):

the absolute worst that can happen is that this panics while panicking and aborts

Joshua Nelson (Oct 04 2020 at 01:54, on Zulip):

but that just turns an ICE -> abort

Camelid (Oct 04 2020 at 01:54, on Zulip):

I'm saying that this could happen on any type, it's just that Ty is the one that triggers this. Is that not true?

Camelid (Oct 04 2020 at 01:55, on Zulip):

So IIUC it's not an issue specific to Ty, it's just where the bug was found

Joshua Nelson (Oct 04 2020 at 01:55, on Zulip):

any type that has a DefPath, yes

Camelid (Oct 04 2020 at 01:56, on Zulip):

I think we're miscommunicating :smile:

Camelid (Oct 04 2020 at 01:57, on Zulip):

Is this issue because of how Debug is implemented for Ty?

Camelid (Oct 04 2020 at 01:57, on Zulip):

(Or some field of Ty?)

Joshua Nelson (Oct 04 2020 at 01:57, on Zulip):

it's because of how Debug is implemented for DefPath, which is one of the fields on Ty

Camelid (Oct 04 2020 at 01:57, on Zulip):

Ah. Let me go look at that PR again

Camelid (Oct 04 2020 at 01:58, on Zulip):

Hmm, but DefPath uses #[derive(Debug)]...

Joshua Nelson (Oct 04 2020 at 01:59, on Zulip):

sorry, this isn't actually Debug, it's print_def_path: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/print/struct.FmtPrinter.html#method.print_def_path

Joshua Nelson (Oct 04 2020 at 01:59, on Zulip):

(it says in the backtrace)

Camelid (Oct 04 2020 at 02:02, on Zulip):

Hmm, still don't see what's causing this

Camelid (Oct 04 2020 at 02:02, on Zulip):

But I guess if it's just for Ty, then P-low probably sounds good

apiraino (Oct 07 2020 at 10:46, on Zulip):

I'll assign a P-low, but open to further reasoning on this

triagebot (Oct 07 2020 at 10:47, on Zulip):

Issue #77458's prioritization request has been removed.

Last update: Apr 11 2021 at 18:15UTC