Stream: t-compiler

Topic: beta regression triage

pnkfelix (Jun 04 2019 at 12:34, on Zulip):

@Pietro Albini pointed out that the Crater results for 1.36 are pretty bad (700 regressions on the check only+rustdoc run) with a link to this comment on the run.

pnkfelix (Jun 04 2019 at 12:38, on Zulip):

Here is a github query that covers unprioritized stable-to-beta regressions that are not already tagged with T-libs nor T-rustdoc

pnkfelix (Jun 04 2019 at 12:38, on Zulip):

that yields 8 issues, lets walk through them.

pnkfelix (Jun 04 2019 at 12:38, on Zulip):

(going to go oldest first)

pnkfelix (Jun 04 2019 at 12:39, on Zulip):

first: "ICE in NLL borrow_check/universal_regions when bounding a trait object with nothing" #61315

pnkfelix (Jun 04 2019 at 12:39, on Zulip):

looks like @Matthew Jasper is on top of it. I'll make it P-high just so I don't have to think about it.

pnkfelix (Jun 04 2019 at 12:40, on Zulip):

next: "regression: failed to parse proc-macro input" #61470

pnkfelix (Jun 04 2019 at 12:41, on Zulip):

petrochenkov has diagnosed this as expected breakage fallout from a bug fix.

pnkfelix (Jun 04 2019 at 12:43, on Zulip):

It seems like the best we can do here is try to update agatan/squeeze-rs ? Its not really a bug we'd do anything in the compiler to address.

pnkfelix (Jun 04 2019 at 12:47, on Zulip):

(and agatan/squeeze-rs looks like it might be abandonware; last update was in Nov 2017...)

pnkfelix (Jun 04 2019 at 12:49, on Zulip):

closing #61470 as not-a-bug/wont-fix.

pnkfelix (Jun 04 2019 at 12:49, on Zulip):

next: "regression: conflicting implementations of trait for Into<Box>" #61471

pnkfelix (Jun 04 2019 at 12:55, on Zulip):

#61471 references two root crates that caused regressions downstream. However, the one that caused the most problems, the owner chimed in saying they had deprecated the crate and linked to the relevant issue. So the question is: Is crater supposed to be blacklisting such cases? (Can it, when there are problems downstream...?)

pnkfelix (Jun 04 2019 at 14:42, on Zulip):

Okay after much investigation, I decided only one crate is actually affected here (the rest are abandoned, I'm pretty sure). I filed an issue against the affected crate and closed #61471.

pnkfelix (Jun 05 2019 at 08:54, on Zulip):

next: "regression: overflow evaluating, Send/Sync?" #61472

pnkfelix (Jun 05 2019 at 08:55, on Zulip):

(presumably due to PR #60444; the running hypothesis that niko and I share is that most instances of this are cases where the input code was unsound, and thus the fallout is expected. I don't think we can readily warning-cycle this change.)

pnkfelix (Jun 05 2019 at 08:58, on Zulip):

I do however want to double check the note made by @Jake Goulding. I assume the discrepancy between behavior observed using rustc vs rustdocis due to some additional code paths being exercised by doc examples.

Last update: May 26 2020 at 13:45UTC