ICE: rustdoc: assertion failed: (left matches right) with non_lifetime_binders

[matthiaskrgr]

I tried this code:

// check-pass
// Basic test that show's we can succesfully typeck a `for<T>` where clause.

#![feature(non_lifetime_binders)]
//~^ WARN the feature `non_lifetime_binders` is incomplete

trait Trait {}

impl<T: ?Sized> Trait for T {}

fn foo()
where
    for<T> T: Trait,
{
}

fn main() {
    foo();
}

Compiles with rustc but rustdoc crashes.

Meta

rustc --version --verbose:

rustdoc 1.69.0-nightly (9556b56db 2023-02-17)
binary: rustdoc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.69.0-nightly
LLVM version: 15.0.7

Backtrace

warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
 --> ./tests/ui/traits/non_lifetime_binders/basic.rs:4:12
  |
4 | #![feature(non_lifetime_binders)]
  |            ^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #1 <https://github.com/rust-lang/rust/issues/1> for more information
  = note: `#[warn(incomplete_features)]` on by default

thread 'rustc' panicked at 'assertion failed: `(left matches right)`
  left: `GenericParam { hir_id: HirId(DefId(0:6 ~ basic[416b]::foo).4), def_id: DefId(0:7 ~ basic[416b]::foo::T), name: Plain(T#0), span: ./tests/ui/traits/non_lifetime_binders/basic.rs:13:9: 13:10 (#0), pure_wrt_drop: false, kind: Type { default: None, synthetic: false }, colon_span: None }`,
 right: `hir::GenericParam { kind: hir::GenericParamKind::Lifetime { .. }, .. }`', src/librustdoc/clean/mod.rs:275:21
stack backtrace:
   0:     0x7f703356aa5a - std::backtrace_rs::backtrace::libunwind::trace::h4f2ddf6c88dbaad9
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f703356aa5a - std::backtrace_rs::backtrace::trace_unsynchronized::h8bc6bf97c95b59de
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f703356aa5a - std::sys_common::backtrace::_print_fmt::h7219a53d43a6b866
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f703356aa5a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h5010216fe7dfec74
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f70335ca9ae - core::fmt::write::h94365b6ce74f4b38
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/core/src/fmt/mod.rs:1232:17
   5:     0x7f703355af05 - std::io::Write::write_fmt::hed6d0d7d7e9fc148
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/io/mod.rs:1684:15
   6:     0x7f703356a825 - std::sys_common::backtrace::_print::h49801225f55874b0
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7f703356a825 - std::sys_common::backtrace::print::h83efbf586cd87643
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7f703356d59f - std::panicking::default_hook::{{closure}}::hb2c05bd9017b98d1
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/panicking.rs:267:22
   9:     0x7f703356d2db - std::panicking::default_hook::hae948cf98c9c5f1a
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/panicking.rs:286:9
  10:     0x7f703686aa14 - rustc_driver_impl[6c2af96379bf1b3f]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f703356dddd - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::he8407b3fffcc824a
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/alloc/src/boxed.rs:2002:9
  12:     0x7f703356dddd - std::panicking::rust_panic_with_hook::h447e2750afeca884
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/panicking.rs:692:13
  13:     0x7f703356db59 - std::panicking::begin_panic_handler::{{closure}}::h61457317657e95be
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/panicking.rs:579:13
  14:     0x7f703356aec6 - std::sys_common::backtrace::__rust_end_short_backtrace::ha398e4defa16c9c2
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys_common/backtrace.rs:137:18
  15:     0x7f703356d862 - rust_begin_unwind
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/panicking.rs:575:5
  16:     0x7f70335c7353 - core::panicking::panic_fmt::h907e7c558a510d58
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/core/src/panicking.rs:64:14
  17:     0x7f70335c776f - core::panicking::assert_failed_inner::h68feff5fb580fb34
  18:     0x55854c8a45f9 - core[dbff95f671937227]::panicking::assert_matches_failed::<&rustc_hir[20d2f58fe67618f5]::hir::GenericParam>
  19:     0x55854c9481c1 - <alloc[d2b9f3df75116eb6]::vec::Vec<rustdoc[d536150884bc5371]::clean::types::Lifetime> as alloc[d2b9f3df75116eb6]::vec::spec_from_iter::SpecFromIter<rustdoc[d536150884bc5371]::clean::types::Lifetime, core[dbff95f671937227]::iter::adapters::map::Map<core[dbff95f671937227]::slice::iter::Iter<rustc_hir[20d2f58fe67618f5]::hir::GenericParam>, rustdoc[d536150884bc5371]::clean::clean_where_predicate::{closure#0}>>>::from_iter
  20:     0x55854cbbd410 - rustdoc[d536150884bc5371]::clean::clean_generics
  21:     0x55854c8cab71 - rustdoc[d536150884bc5371]::clean::utils::enter_impl_trait::<rustdoc[d536150884bc5371]::clean::clean_function::{closure#0}, (rustdoc[d536150884bc5371]::clean::types::Generics, rustdoc[d536150884bc5371]::clean::types::FnDecl)>
  22:     0x55854cbc0994 - rustdoc[d536150884bc5371]::clean::clean_fn_or_proc_macro
  23:     0x55854cb38f78 - <rustdoc[d536150884bc5371]::core::DocContext>::with_param_env::<alloc[d2b9f3df75116eb6]::vec::Vec<rustdoc[d536150884bc5371]::clean::types::Item>, rustdoc[d536150884bc5371]::clean::clean_maybe_renamed_item::{closure#1}>
  24:     0x55854cbad423 - <&mut rustdoc[d536150884bc5371]::clean::clean_doc_module::{closure#2} as core[dbff95f671937227]::ops::function::FnOnce<(&(&rustc_hir[20d2f58fe67618f5]::hir::Item, core[dbff95f671937227]::option::Option<rustc_span[f167ea544e4ee22c]::symbol::Symbol>, core[dbff95f671937227]::option::Option<rustc_span[f167ea544e4ee22c]::def_id::LocalDefId>),)>>::call_once
  25:     0x55854c9393bb - <alloc[d2b9f3df75116eb6]::vec::Vec<rustdoc[d536150884bc5371]::clean::types::Item> as alloc[d2b9f3df75116eb6]::vec::spec_extend::SpecExtend<rustdoc[d536150884bc5371]::clean::types::Item, core[dbff95f671937227]::iter::adapters::flatten::FlatMap<core[dbff95f671937227]::slice::iter::Iter<(&rustc_hir[20d2f58fe67618f5]::hir::Item, core[dbff95f671937227]::option::Option<rustc_span[f167ea544e4ee22c]::symbol::Symbol>, core[dbff95f671937227]::option::Option<rustc_span[f167ea544e4ee22c]::def_id::LocalDefId>)>, alloc[d2b9f3df75116eb6]::vec::Vec<rustdoc[d536150884bc5371]::clean::types::Item>, rustdoc[d536150884bc5371]::clean::clean_doc_module::{closure#2}>>>::spec_extend
  26:     0x55854cbba96d - rustdoc[d536150884bc5371]::clean::clean_doc_module
  27:     0x55854c8c449c - rustdoc[d536150884bc5371]::clean::utils::krate
  28:     0x55854caad374 - <rustc_session[c15eaeef136f5e4a]::session::Session>::time::<rustdoc[d536150884bc5371]::clean::types::Crate, rustdoc[d536150884bc5371]::core::run_global_ctxt::{closure#4}>
  29:     0x55854cb3d3ba - rustdoc[d536150884bc5371]::core::run_global_ctxt
  30:     0x55854caad729 - <rustc_session[c15eaeef136f5e4a]::session::Session>::time::<(rustdoc[d536150884bc5371]::clean::types::Crate, rustdoc[d536150884bc5371]::config::RenderOptions, rustdoc[d536150884bc5371]::formats::cache::Cache), rustdoc[d536150884bc5371]::main_args::{closure#1}::{closure#0}::{closure#0}::{closure#0}>
  31:     0x55854c88ab87 - <rustc_middle[9f8d2e014f13ace2]::ty::context::GlobalCtxt>::enter::<rustdoc[d536150884bc5371]::main_args::{closure#1}::{closure#0}::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>
  32:     0x55854c997d20 - <rustc_interface[3f0b305400f2a575]::interface::Compiler>::enter::<rustdoc[d536150884bc5371]::main_args::{closure#1}::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>
  33:     0x55854caabf6b - rustc_span[f167ea544e4ee22c]::with_source_map::<core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>, rustc_interface[3f0b305400f2a575]::interface::run_compiler<core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>, rustdoc[d536150884bc5371]::main_args::{closure#1}>::{closure#0}::{closure#0}>
  34:     0x55854c99b9e2 - <scoped_tls[b36333e7b7cf83b9]::ScopedKey<rustc_span[f167ea544e4ee22c]::SessionGlobals>>::set::<rustc_interface[3f0b305400f2a575]::interface::run_compiler<core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>, rustdoc[d536150884bc5371]::main_args::{closure#1}>::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>
  35:     0x55854cabb810 - std[37372fc96080da93]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3f0b305400f2a575]::util::run_in_thread_pool_with_globals<rustc_interface[3f0b305400f2a575]::interface::run_compiler<core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>, rustdoc[d536150884bc5371]::main_args::{closure#1}>::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>
  36:     0x55854cb2f847 - <<std[37372fc96080da93]::thread::Builder>::spawn_unchecked_<rustc_interface[3f0b305400f2a575]::util::run_in_thread_pool_with_globals<rustc_interface[3f0b305400f2a575]::interface::run_compiler<core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>, rustdoc[d536150884bc5371]::main_args::{closure#1}>::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[dbff95f671937227]::result::Result<(), rustc_errors[26f6982c64bee1b3]::ErrorGuaranteed>>::{closure#1} as core[dbff95f671937227]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  37:     0x7f7033577c63 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h6cb6b9d9103f983c
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/alloc/src/boxed.rs:1988:9
  38:     0x7f7033577c63 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h11325854ceea5259
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/alloc/src/boxed.rs:1988:9
  39:     0x7f7033577c63 - std::sys::unix::thread::Thread::new::thread_start::h5bdb2262729f1e24
                               at /rustc/9556b56dbdbd4238f0051e7230004b0aa488fa14/library/std/src/sys/unix/thread.rs:108:17
  40:     0x7f70332b0bb5 - <unknown>
  41:     0x7f7033332d90 - <unknown>
  42:                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-compiler&template=ice.md

note: rustc 1.69.0-nightly (9556b56db 2023-02-17) running on x86_64-unknown-linux-gnu

query stack during panic:
end of query stack
warning: 1 warning emitted

[langston-barrett]

@rustbot label +S-bug-has-mcve