regression: expected one of !, (, +, ::, <, >, or as, found :

[BoxyUwU]

• https://crater-reports.s3.amazonaws.com/beta-1.81-2/beta-2024-07-26/gh/go-bazzinga.yral-identity/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.81-2/beta-2024-07-26/gh/jwiegley.delta/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.81-2/beta-2024-07-26/reg/comparable-0.5.4/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.81-2/beta-2024-07-26/reg/elevenlabs_rs-0.2.0/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.81-2/beta-2024-07-26/reg/stability_rs-0.1.0/log.txt

[INFO] [stdout] error: expected one of `!`, `(`, `+`, `::`, `<`, `>`, or `as`, found `:`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/comparable-0.5.4/src/tuple.rs:8:9
[INFO] [stdout]    |
[INFO] [stdout] 8  |         comparable_helper::impl_comparable_for_tuple!(($b,$($a),+));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected one of 7 possible tokens
[INFO] [stdout] ...
[INFO] [stdout] 13 | impl_all!(A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12);
[INFO] [stdout]    | ------------------------------------------------------------ in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: this error originates in the macro `comparable_helper::impl_comparable_for_tuple` which comes from the expansion of the macro `impl_all` (in Nightly builds, run with -Z macro-backtrace for more info)

[compiler-errors]

This regressed in #127636, cc @nnethercote

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high

[apiraino]

hope it's ok to close this as the beta backport of #128994 was approved