Crash when formatting complex file

[mobiusklein]

cargo fmt and cargo rustfmt crash when processing https://github.com/mobiusklein/mzdata/blob/34b2d6feb3201140991fa66b53960ab8141c7ed7/src/io/infer_format.rs. See below for traceback.

Toolchain: stable-x86_64-pc-windows-msvc
Version: rustc 1.76.0 (07dca489a 2024-02-04)
Platform: Windows 10

Supposition

This file specifically started to crash the formatter when I added a few large, complex generic algebraic types, Source and Sink, and another generic-heavy trait to consume them, MassSpectrometryReadWriteProcess.

Traceback:

Details

hread 'main' panicked at src\tools\rustfmt\src\items.rs:547:10:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0:     0x7fffed4822c2 - ::fmt::h7851e041f2b8bcc2
   1:     0x7fffed4b4cdd - core::fmt::write::h1642dfca37b49735
   2:     0x7fffed478ca1 - ::fmt::h7801514a6fc13a4a
   3:     0x7fffed4820ea - std::sys_common::backtrace::lock::h8caaa69a6cc2258b
   4:     0x7fffed485529 - std::panicking::default_hook::h67f6260a0bf37eca
   5:     0x7fffed4851e5 - std::panicking::default_hook::h67f6260a0bf37eca
   6:     0x7ffff1d0fb03 - ::write_fmt
   7:     0x7fffed485b43 - std::panicking::rust_panic_with_hook::h870983d929e74e12
   8:     0x7fffed4859ab - ::take_box::h971268ed26284d4c
   9:     0x7fffed482bc9 - ::fmt::h7851e041f2b8bcc2
  10:     0x7fffed4856b2 - rust_begin_unwind
  11:     0x7fffed4da447 - core::panicking::panic_fmt::ha5dd7a91f3010b68
  12:     0x7fffed4da522 - core::panicking::panic::h61d0277f5e1a7407
  13:     0x7ff64a524bde - 
  14:     0x7ff64a51c2d6 - 
  15:     0x7ff64a52a2ea - 
  16:     0x7ff64a4992b8 - 
  17:     0x7ff64a49fa3b - 
  18:     0x7ff64a49cf53 - 
  19:     0x7ff64a497690 - 
  20:     0x7ff64a482682 - 
  21:     0x7ff64a4961af - 
  22:     0x7ff64a4806bf - 
  23:     0x7ff64a47e5c4 - 
  24:     0x7ff64a49bcb6 - 
  25:     0x7ff64a4974dc - 
  26:     0x7fffed46ae32 - std::rt::lang_start_internal::h68f55995b3e4e811
  27:     0x7ff64a4834fc - 
  28:     0x7ff64a83acbc - 
  29:     0x7ff8b1ea7344 - BaseThreadInitThunk
  30:     0x7ff8b35426b1 - RtlUserThreadStart

[ytmimi]

Thanks for the report. This feels like it's related to #5738.

Here's a smaller reproducible test case:

enum MZReaderType<
    D: DeconvolutedCentroidLike + Default + From<DeconvolutedPeak> + BuildFromArrayMap=DeconvolutedPeak
> {}

[calebcartwright]

I'm going to minimize some of these comments as they feel orthogonal to this particular issue, and are representative of issues experienced by a user (@iddm) that have been reported across multiple issues (#2615)

@iddm as I stated on #2615 a new issue would be helpful for discussion. The issue seems to be specific to you/your local environment, if libcore was panicking for everyone everywhere then yes, that'd be quite a high priority issue across a number of tools and teams.