Crash during rustfmt

[douweschulte]

I ran cargo fmt on a crate and this was the response.

thread 'main' panicked at src\tools\rustfmt\src\items.rs:548:10:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0:     0x7ffd0db30f51 - std::backtrace_rs::backtrace::dbghelp64::trace
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\..\..\backtrace\src\backtrace\dbghelp64.rs:91
   1:     0x7ffd0db30f51 - std::backtrace_rs::backtrace::trace_unsynchronized
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\..\..\backtrace\src\backtrace\mod.rs:66
   2:     0x7ffd0db30f51 - std::sys::backtrace::_print_fmt
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\sys\backtrace.rs:66
   3:     0x7ffd0db30f51 - std::sys::backtrace::impl$0::print::impl$0::fmt
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\sys\backtrace.rs:39
   4:     0x7ffd0db62629 - core::fmt::rt::Argument::fmt
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/core\src\fmt\rt.rs:177
   5:     0x7ffd0db62629 - core::fmt::write
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/core\src\fmt\mod.rs:1178
   6:     0x7ffd0db27117 - std::io::Write::write_fmt<std::sys::pal::windows::stdio::Stderr>
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\io\mod.rs:1823
   7:     0x7ffd0db34069 - std::panicking::default_hook::closure$1
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:266
   8:     0x7ffd0db33bec - std::panicking::default_hook
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:293
   9:     0x7ffd0f085e40 - memchr
  10:     0x7ffd0db34a7b - alloc::boxed::impl$50::call
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/alloc\src\boxed.rs:2245
  11:     0x7ffd0db34a7b - std::panicking::rust_panic_with_hook
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:805
  12:     0x7ffd0db3484f - std::panicking::begin_panic_handler::closure$0
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:664
  13:     0x7ffd0db31a0f - std::sys::backtrace::__rust_end_short_backtrace<std::panicking::begin_panic_handler::closure_env$0,never$>
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\sys\backtrace.rs:170
  14:     0x7ffd0db34496 - std::panicking::begin_panic_handler
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:662
  15:     0x7ffd108f47d4 - core::panicking::panic_fmt
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/core\src\panicking.rs:74
  16:     0x7ffd108f487d - core::panicking::panic
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/core\src\panicking.rs:148
  17:     0x7ffd108f473e - core::option::unwrap_failed
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/core\src\option.rs:2015
  18:     0x7ff737826bea - <unknown>
  19:     0x7ff7378976b0 - <unknown>
  20:     0x7ff7378779ed - <unknown>
  21:     0x7ff73789cfd6 - <unknown>
  22:     0x7ff7376c3b7a - <unknown>
  23:     0x7ff7376f3290 - <unknown>
  24:     0x7ff7376ee98d - <unknown>
  25:     0x7ff7376ea332 - <unknown>
  26:     0x7ff7376dd006 - <unknown>
  27:     0x7ff7376dd6cc - <unknown>
  28:     0x7ffd0db17ff9 - std::rt::lang_start_internal::closure$2
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\rt.rs:143
  29:     0x7ffd0db17ff9 - std::panicking::try::do_call
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:554
  30:     0x7ffd0db17ff9 - std::panicking::try
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panicking.rs:518
  31:     0x7ffd0db17ff9 - std::panic::catch_unwind
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\panic.rs:345
  32:     0x7ffd0db17ff9 - std::rt::lang_start_internal
                               at /rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14\library/std\src\rt.rs:143
  33:     0x7ff7376f46cc - <unknown>
  34:     0x7ff737a0de50 - <unknown>
  35:     0x7ffdf5b6257d - BaseThreadInitThunk
  36:     0x7ffdf778af08 - RtlUserThreadStart

error: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rustfmt/issues/new?labels=bug

note: rustc 1.82.0 (f6e511eec 2024-10-15) running on x86_64-pc-windows-msvc

query stack during panic:
end of query stack

I was working on the following codebase [github.com/douweschulte/mzdata] and made a snapshot commit of the state when the crash happened. If I can help by providing more information let me know.

[ytmimi]

@douweschulte Thanks for reaching out and reporting the crash. It would be really helpful to provide a minimal code snippet that reproduces the crash, otherwise it's going to be a lot harder to get to the bottom of this issue.

It would also be helpful to know what version of rustfmt you were using and if you were using any configuration options.

[ytmimi]

Based off of the info in the backtrace I suspect this is related to #5738, possibly a duplicate.