Repository: rust
Issue: rustdoc crashes on associated type projections
Labels: T-rustdoc,I-ICE,C-bug,A-synthetic-impls,A-auto-traits

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### Code

```Rust
pub struct Struct<T>
where
    T: Trait<Type2 = ()>,
{
    pub field: T::Type1,
}
pub trait Trait: BaseTrait<Type1 = <Self as Trait>::Type2> {
    type Type2;
}
pub trait BaseTrait {
    type Type1;
}
```


### Meta
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If you're using the stable version of the compiler, you should also check if the
bug also exists in the beta or nightly versions.
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`rustc --version --verbose`:
```
rustc 1.79.0 (129f3b996 2024-06-10)
binary: rustc
commit-hash: 129f3b9964af4d4a709d1383930ade12dfe7c081
commit-date: 2024-06-10
host: x86_64-unknown-linux-gnu
release: 1.79.0
LLVM version: 18.1.7
```

bug also occurs on nightly

`rustc --version --verbose`:
```
rustc 1.81.0-nightly (0c81f94b9 2024-07-10)
binary: rustc
commit-hash: 0c81f94b9a6207fb1fc080caa83584dea2d71fc6
commit-date: 2024-07-10
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7
```

### Error output

```
thread 'rustc' panicked at compiler/rustc_trait_selection/src/traits/auto_trait.rs:728:33:
Unexpected result when selecting Struct<T/#0> Obligation(predicate=Binder { value: ProjectionPredicate(AliasTerm { args: [T/#0], def_id: DefId(0:9 ~ lib[e681]::BaseTrait::Type1) }, Term::Ty(?0t)), bound_vars: [] }, depth=2)
```

[rustc-ice-2024-07-11T03_38_08-433375.txt](https://github.com/user-attachments/files/16171120/rustc-ice-2024-07-11T03_38_08-433375.txt)

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Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
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<details><summary><strong>Backtrace</strong></summary>
<p>

```
stack backtrace:
   0:     0x7f29816b6655 - std::backtrace_rs::backtrace::libunwind::trace::ha33d49b62179466d
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
   1:     0x7f29816b6655 - std::backtrace_rs::backtrace::trace_unsynchronized::h62aca976e31fe218
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f29816b6655 - std::sys::backtrace::_print_fmt::hca96100d9e18721f
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/backtrace.rs:68:5
   3:     0x7f29816b6655 - <std::sys::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hf8366c5ef1b524a9
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/backtrace.rs:44:22
   4:     0x7f2981705d3b - core::fmt::rt::Argument::fmt::h7fd777d4d54cce4a
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/core/src/fmt/rt.rs:173:76
   5:     0x7f2981705d3b - core::fmt::write::ha5f64323c8f45816
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/core/src/fmt/mod.rs:1182:21
   6:     0x7f29816aaf8f - std::io::Write::write_fmt::h009396e769a8aa9b
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/io/mod.rs:1835:15
   7:     0x7f29816b642e - std::sys::backtrace::_print::h193bb74a56dbb373
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/backtrace.rs:47:5
   8:     0x7f29816b642e - std::sys::backtrace::print::h2895220bf278ca26
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/backtrace.rs:34:9
   9:     0x7f29816b8d79 - std::panicking::default_hook::{{closure}}::had1eb0933af91d17
  10:     0x7f29816b8b1c - std::panicking::default_hook::h77401536babb35bd
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/panicking.rs:292:9
  11:     0x7f2984b594da - std[69163dc58001fbdc]::panicking::update_hook::<alloc[3d433dcf797e1c4c]::boxed::Box<rustc_driver_impl[17a8534abb3728b2]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f29816b969f - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h46ff1cf8739abfbf
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/alloc/src/boxed.rs:2078:9
  13:     0x7f29816b969f - std::panicking::rust_panic_with_hook::hb2f290c059c9227c
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/panicking.rs:804:13
  14:     0x7f29816b92c7 - std::panicking::begin_panic_handler::{{closure}}::hbdd6dbac1d79bc65
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/panicking.rs:670:13
  15:     0x7f29816b6b19 - std::sys::backtrace::__rust_end_short_backtrace::habe2c623ddb8abb4
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/backtrace.rs:171:18
  16:     0x7f29816b8f54 - rust_begin_unwind
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/panicking.rs:661:5
  17:     0x7f29817022f3 - core::panicking::panic_fmt::hf48eda04dd8cb30c
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/core/src/panicking.rs:74:14
  18:     0x7f298581c0b0 - <rustc_trait_selection[32ec608b802ae219]::traits::auto_trait::AutoTraitFinder>::evaluate_predicates
  19:     0x55f996befdd9 - rustdoc[da0500aaae5a6627]::clean::auto_trait::synthesize_auto_trait_impl
  20:     0x55f996aac1d8 - rustdoc[da0500aaae5a6627]::clean::utils::synthesize_auto_trait_and_blanket_impls
  21:     0x55f996bc4cf1 - <rustdoc[da0500aaae5a6627]::passes::collect_trait_impls::SyntheticImplCollector as rustdoc[da0500aaae5a6627]::visit::DocVisitor>::visit_item
  22:     0x55f996bc4fea - <rustdoc[da0500aaae5a6627]::passes::collect_trait_impls::SyntheticImplCollector as rustdoc[da0500aaae5a6627]::visit::DocVisitor>::visit_item
  23:     0x55f996bc177e - rustdoc[da0500aaae5a6627]::passes::collect_trait_impls::collect_trait_impls
  24:     0x55f996adbaac - rustdoc[da0500aaae5a6627]::core::run_global_ctxt
  25:     0x55f996994fb8 - <rustc_middle[f955c2d190e152df]::ty::context::GlobalCtxt>::enter::<rustdoc[da0500aaae5a6627]::main_args::{closure#1}::{closure#0}::{closure#0}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#1}
  26:     0x55f99699ebc7 - rustc_interface[850405b0f2da8be8]::interface::run_compiler::<core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>, rustdoc[da0500aaae5a6627]::main_args::{closure#1}>::{closure#1}
  27:     0x55f99692a575 - std[69163dc58001fbdc]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[850405b0f2da8be8]::util::run_in_thread_with_globals<rustc_interface[850405b0f2da8be8]::util::run_in_thread_pool_with_globals<rustc_interface[850405b0f2da8be8]::interface::run_compiler<core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>, rustdoc[da0500aaae5a6627]::main_args::{closure#1}>::{closure#1}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#0}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>
  28:     0x55f9969a9f47 - <<std[69163dc58001fbdc]::thread::Builder>::spawn_unchecked_<rustc_interface[850405b0f2da8be8]::util::run_in_thread_with_globals<rustc_interface[850405b0f2da8be8]::util::run_in_thread_pool_with_globals<rustc_interface[850405b0f2da8be8]::interface::run_compiler<core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>, rustdoc[da0500aaae5a6627]::main_args::{closure#1}>::{closure#1}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#0}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[168fded7e7f0f235]::result::Result<(), rustc_span[fe275b7a592f40ac]::ErrorGuaranteed>>::{closure#2} as core[168fded7e7f0f235]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  29:     0x7f29816c34fb - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd131f6f2527e7623
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/alloc/src/boxed.rs:2064:9
  30:     0x7f29816c34fb - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hde4508abfffa77b1
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/alloc/src/boxed.rs:2064:9
  31:     0x7f29816c34fb - std::sys::pal::unix::thread::Thread::new::thread_start::ha2d1c999409fd904
                               at /rustc/0c81f94b9a6207fb1fc080caa83584dea2d71fc6/library/std/src/sys/pal/unix/thread.rs:108:17
  32:     0x7f2981585609 - start_thread
                               at /build/glibc-LcI20x/glibc-2.31/nptl/pthread_create.c:477:8
  33:     0x7f2981359353 - clone
                               at /build/glibc-LcI20x/glibc-2.31/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95
  34:                0x0 - <unknown>

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: please make sure that you have updated to the latest nightly

note: please attach the file at `/home/jacob/projects/fayalite/rustc-ice-2024-07-11T03_38_08-433375.txt` to your bug report

query stack during panic:
end of query stack
```

</p>
</details>