rustdoc: ICE: synthetic auto trait impls: `unexpected result when selecting […] obligation`

[cboudereau]

The error is also available at docs.rs build failure : https://docs.rs/crate/dataseries/0.1.0/builds/870326

Meta

rustc --version --verbose:
stable :

rustc 1.71.0 (8ede3aae2 2023-07-12)
binary: rustc
commit-hash: 8ede3aae28fe6e4d52b38157d7bfe0d3bceef225
commit-date: 2023-07-12
host: x86_64-pc-windows-msvc
release: 1.71.0
LLVM version: 16.0.5

nightly:

note: rustc 1.73.0-nightly (864bdf784 2023-07-25) running on x86_64-pc-windows-msvc

note: compiler flags: --crate-type lib

note: some of the compiler flags provided by cargo are hidden

Error output

thread 'rustc' panicked at 'Unexpected result when selecting union::Union<P, L, R, F> Obligation(predicate=Binder(ProjectionPredicate(AliasTy { substs: [L], def_id: DefId(2:7329 ~ core[2122]::iter::traits::iterator::Iterator::Item) }, Term::Ty(_)), []), depth=2)', compiler\rustc_trait_selection\src\traits\auto_trait.rs:756:33
stack backtrace:
   0:     0x7ffbec16606c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h3e1167d1197708e4            
   1:     0x7ffbec19f35b - core::fmt::write::hac390ab77a0546f0
   2:     0x7ffbec15b7c9 - <std::io::IoSlice as core::fmt::Debug>::fmt::h0070e976aab63c36
   3:     0x7ffbec165e1b - std::sys::common::alloc::realloc_fallback::h06192b62f610af21                                                    
   4:     0x7ffbec169679 - std::panicking::default_hook::hdd9fc6bbf54f9f24
   5:     0x7ffbec16932f - std::panicking::default_hook::hdd9fc6bbf54f9f24
   6:     0x7ffbdeaaab66 - rustc_driver_impl[987711191ffbfbfa]::install_ice_hook
   7:     0x7ffbec169da0 - std::panicking::rust_panic_with_hook::hd8f3ae1c8ed0dc2b
   8:     0x7ffbec169b2d - <std::panicking::begin_panic_handler::StrPanicPayload as core::panic::BoxMeUp>::get::h5835203c41f72561
   9:     0x7ffbec166c99 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h3e1167d1197708e4
  10:     0x7ffbec169830 - rust_begin_unwind
  11:     0x7ffbec1d2b35 - core::panicking::panic_fmt::h5eb23ef5cbd3b939
  12:     0x7ffbe06a93ea - <rustc_trait_selection[ad4f6560a7a1afa4]::traits::auto_trait::AutoTraitFinder>::evaluate_predicates
  13:     0x7ff70af5e198 - <unknown>
  14:     0x7ff70b07ac7b - <unknown>
  15:     0x7ff70aeb4044 - <unknown>
  16:     0x7ff70b07b68f - <unknown>
  17:     0x7ff70afe6a5b - <unknown>
  18:     0x7ff70afa5ccc - <unknown>
  19:     0x7ff70afa5dac - <unknown>
  20:     0x7ff70afa5dac - <unknown>
  21:     0x7ff70afa6c21 - <unknown>
  22:     0x7ff70b002dd2 - <unknown>
  23:     0x7ff70afa2dc9 - <unknown>
  24:     0x7ff70b0031f1 - <unknown>
  25:     0x7ff70af49cdd - <unknown>
  26:     0x7ff70b00377f - <unknown>
  27:     0x7ff70ae45e5b - <unknown>
  28:     0x7ff70afabff8 - <unknown>
  29:     0x7ff70b0c7dff - <unknown>
  30:     0x7ff70ae0e86a - <unknown>
  31:     0x7ff70b064116 - <unknown>
  32:     0x7ff70af299b5 - <unknown>
  33:     0x7ffbec17d22c - std::sys::windows::thread::Thread::new::h3304e03edc5e66c6
  34:     0x7ffc49697614 - BaseThreadInitThunk
  35:     0x7ffc4a0c26b1 - RtlUserThreadStart

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md    

note: rustc 1.71.0 (8ede3aae2 2023-07-12) running on x86_64-pc-windows-msvc

note: compiler flags: --crate-type lib

note: some of the compiler flags provided by cargo are hidden

[fmease]

@rustbot label -needs-triage T-rustdoc A-synthetic-impls A-auto-traits

(this is a matter for both T-compiler and T-rustdoc as AutoTraitFinder partially lives in rustc (theoretically available to non-rustdoc tools), partially in rustdoc).

Related to (if not duplicate of one of) #105199, #107715.