ICE: escaping bound vars in predicate Obligation in inherited.rs

[langston-barrett]

Found this while minimizing #109054 😄 So maybe related?

These didn't seem like duplicates.

Code

#![feature(type_alias_impl_trait)]
struct S;
type ReturnType<'a> = impl Eq + 'a;
impl std::ops::Deref for S {
    type Target = dyn Fn(&()) -> ReturnType;
    fn deref() -> &'static Self::Target {}
}

Meta

rustc --version --verbose:

rustc 1.70.0-nightly (511364e78 2023-03-16)
binary: rustc
commit-hash: 511364e7874dba9649a264100407e4bffe7b5425
commit-date: 2023-03-16
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7

Error output

Backtrace

error: internal compiler error: compiler/rustc_hir_typeck/src/inherited.rs:105:13: escaping bound vars in predicate Obligation(predicate=Binder(TraitPredicate(<ReturnType<'_> as std::marker::Sized>, polarity:Positive), []), depth=0)
 --> melted.rs:6:19
  |
6 |     fn deref() -> &'static Self::Target {}
  |                   ^^^^^^^^^^^^^^^^^^^^^

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/511364e7874dba9649a264100407e4bffe7b5425/compiler/rustc_errors/src/lib.rs:995:33
stack backtrace:
   0:     0x7f4bd00b250a - std::backtrace_rs::backtrace::libunwind::trace::h245cf0f2a6c541d3
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f4bd00b250a - std::backtrace_rs::backtrace::trace_unsynchronized::hb9c09f0c27ccd9c2
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f4bd00b250a - std::sys_common::backtrace::_print_fmt::h80542a6be873a587
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f4bd00b250a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h173aa0e4922bf51c
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f4bd0115b3e - core::fmt::write::ha8661072c4235e29
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/core/src/fmt/mod.rs:1254:17
   5:     0x7f4bd00a5375 - std::io::Write::write_fmt::hf0bf0ac3e42e8a7e
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/io/mod.rs:1684:15
   6:     0x7f4bd00b22d5 - std::sys_common::backtrace::_print::h4af6a629a9994a8b
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7f4bd00b22d5 - std::sys_common::backtrace::print::hdccd3478dffb762f
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7f4bd00b504f - std::panicking::default_hook::{{closure}}::heabec2697510ca4b
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/panicking.rs:271:22
   9:     0x7f4bd00b4d8b - std::panicking::default_hook::hf7d16e5638b7d15e
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/panicking.rs:290:9
  10:     0x7f4bd339c1c5 - rustc_driver_impl[1234c7df5b953713]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f4bd00b588d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hfc618573a7a4ac85
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/alloc/src/boxed.rs:2002:9
  12:     0x7f4bd00b588d - std::panicking::rust_panic_with_hook::hcbf73c2ba2c5f60a
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/panicking.rs:696:13
  13:     0x7f4bd35c6321 - std[8d8990c2ba4fc99a]::panicking::begin_panic::<rustc_errors[116146ae72f5b2a5]::ExplicitBug>::{closure#0}
  14:     0x7f4bd35c37e6 - std[8d8990c2ba4fc99a]::sys_common::backtrace::__rust_end_short_backtrace::<std[8d8990c2ba4fc99a]::panicking::begin_panic<rustc_errors[116146ae72f5b2a5]::ExplicitBug>::{closure#0}, !>
  15:     0x7f4bd35f5d66 - std[8d8990c2ba4fc99a]::panicking::begin_panic::<rustc_errors[116146ae72f5b2a5]::ExplicitBug>
  16:     0x7f4bd35c0666 - std[8d8990c2ba4fc99a]::panic::panic_any::<rustc_errors[116146ae72f5b2a5]::ExplicitBug>
  17:     0x7f4bd35bad02 - <rustc_errors[116146ae72f5b2a5]::HandlerInner>::span_bug::<rustc_span[a41f956c2bae68ea]::span_encoding::Span, &alloc[d45f47a36059466c]::string::String>
  18:     0x7f4bd35baad7 - <rustc_errors[116146ae72f5b2a5]::Handler>::span_bug::<rustc_span[a41f956c2bae68ea]::span_encoding::Span, &alloc[d45f47a36059466c]::string::String>
  19:     0x7f4bd3645e4b - rustc_middle[fef03dd4a87f24e7]::util::bug::opt_span_bug_fmt::<rustc_span[a41f956c2bae68ea]::span_encoding::Span>::{closure#0}
  20:     0x7f4bd3645e9a - rustc_middle[fef03dd4a87f24e7]::ty::context::tls::with_opt::<rustc_middle[fef03dd4a87f24e7]::util::bug::opt_span_bug_fmt<rustc_span[a41f956c2bae68ea]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7f4bd3644166 - rustc_middle[fef03dd4a87f24e7]::ty::context::tls::with_context_opt::<rustc_middle[fef03dd4a87f24e7]::ty::context::tls::with_opt<rustc_middle[fef03dd4a87f24e7]::util::bug::opt_span_bug_fmt<rustc_span[a41f956c2bae68ea]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7f4bd3644106 - rustc_middle[fef03dd4a87f24e7]::util::bug::opt_span_bug_fmt::<rustc_span[a41f956c2bae68ea]::span_encoding::Span>
  23:     0x7f4bd17938d4 - rustc_middle[fef03dd4a87f24e7]::util::bug::span_bug_fmt::<rustc_span[a41f956c2bae68ea]::span_encoding::Span>
  24:     0x7f4bd1794e12 - <rustc_hir_typeck[7583ab7f8f5b1ce2]::inherited::Inherited>::register_infer_ok_obligations::<rustc_middle[fef03dd4a87f24e7]::ty::Ty>
  25:     0x7f4bd238ca1d - rustc_hir_typeck[7583ab7f8f5b1ce2]::check::check_fn
  26:     0x7f4bd23766f4 - rustc_hir_typeck[7583ab7f8f5b1ce2]::typeck
  27:     0x7f4bd1d41c66 - rustc_query_system[e4d6cb21d96a044c]::query::plumbing::try_execute_query::<rustc_query_impl[8d521fe1c118fabd]::queries::typeck, rustc_query_impl[8d521fe1c118fabd]::plumbing::QueryCtxt>
  28:     0x7f4bd1d415c3 - <rustc_query_impl[8d521fe1c118fabd]::Queries as rustc_middle[fef03dd4a87f24e7]::ty::query::QueryEngine>::typeck
  29:     0x7f4bd35191b5 - <rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator>::check
  30:     0x7f4bd35166d2 - <rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator as rustc_hir[73843cfc1da40d3a]::intravisit::Visitor>::visit_nested_impl_item
  31:     0x7f4bd34f2566 - rustc_hir[73843cfc1da40d3a]::intravisit::walk_item::<rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator>
  32:     0x7f4bd35165fd - <rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator as rustc_hir[73843cfc1da40d3a]::intravisit::Visitor>::visit_nested_item
  33:     0x7f4bd34f0738 - rustc_hir[73843cfc1da40d3a]::intravisit::walk_mod::<rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator>
  34:     0x7f4bd3518b01 - rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::find_opaque_ty_constraints_for_tait
  35:     0x7f4bd2aa891d - rustc_hir_analysis[f9cb05146d6e270d]::collect::type_of::type_of
  36:     0x7f4bd1c8d38d - rustc_query_system[e4d6cb21d96a044c]::query::plumbing::try_execute_query::<rustc_query_impl[8d521fe1c118fabd]::queries::type_of, rustc_query_impl[8d521fe1c118fabd]::plumbing::QueryCtxt>
  37:     0x7f4bd1c8bf9d - <rustc_query_impl[8d521fe1c118fabd]::Queries as rustc_middle[fef03dd4a87f24e7]::ty::query::QueryEngine>::type_of
  38:     0x7f4bd20ab51b - rustc_hir_analysis[f9cb05146d6e270d]::check::check::check_mod_item_types
  39:     0x7f4bd29de645 - rustc_query_system[e4d6cb21d96a044c]::query::plumbing::try_execute_query::<rustc_query_impl[8d521fe1c118fabd]::queries::check_mod_item_types, rustc_query_impl[8d521fe1c118fabd]::plumbing::QueryCtxt>
  40:     0x7f4bd29de243 - <rustc_query_impl[8d521fe1c118fabd]::Queries as rustc_middle[fef03dd4a87f24e7]::ty::query::QueryEngine>::check_mod_item_types
  41:     0x7f4bd1700654 - <rustc_session[b62839d35778be9]::session::Session>::time::<(), rustc_hir_analysis[f9cb05146d6e270d]::check_crate::{closure#6}>
  42:     0x7f4bd16fd4f8 - rustc_hir_analysis[f9cb05146d6e270d]::check_crate
  43:     0x7f4bd16f4362 - rustc_interface[fc89f7f2ae9d232a]::passes::analysis
  44:     0x7f4bd2bb5e8c - rustc_query_system[e4d6cb21d96a044c]::query::plumbing::try_execute_query::<rustc_query_impl[8d521fe1c118fabd]::queries::analysis, rustc_query_impl[8d521fe1c118fabd]::plumbing::QueryCtxt>
  45:     0x7f4bd2bb5b80 - <rustc_query_impl[8d521fe1c118fabd]::Queries as rustc_middle[fef03dd4a87f24e7]::ty::query::QueryEngine>::analysis
  46:     0x7f4bd2a0de09 - <rustc_middle[fef03dd4a87f24e7]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[1234c7df5b953713]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>
  47:     0x7f4bd25a5e6d - <rustc_interface[fc89f7f2ae9d232a]::interface::Compiler>::enter::<rustc_driver_impl[1234c7df5b953713]::run_compiler::{closure#1}::{closure#2}, core[f4906066c81ab25f]::result::Result<core[f4906066c81ab25f]::option::Option<rustc_interface[fc89f7f2ae9d232a]::queries::Linker>, rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>
  48:     0x7f4bd25a3f56 - rustc_span[a41f956c2bae68ea]::with_source_map::<core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>, rustc_interface[fc89f7f2ae9d232a]::interface::run_compiler<core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>, rustc_driver_impl[1234c7df5b953713]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  49:     0x7f4bd25a34e9 - std[8d8990c2ba4fc99a]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[fc89f7f2ae9d232a]::util::run_in_thread_pool_with_globals<rustc_interface[fc89f7f2ae9d232a]::interface::run_compiler<core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>, rustc_driver_impl[1234c7df5b953713]::run_compiler::{closure#1}>::{closure#0}, core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>
  50:     0x7f4bd2c8be8a - <<std[8d8990c2ba4fc99a]::thread::Builder>::spawn_unchecked_<rustc_interface[fc89f7f2ae9d232a]::util::run_in_thread_pool_with_globals<rustc_interface[fc89f7f2ae9d232a]::interface::run_compiler<core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>, rustc_driver_impl[1234c7df5b953713]::run_compiler::{closure#1}>::{closure#0}, core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[f4906066c81ab25f]::result::Result<(), rustc_span[a41f956c2bae68ea]::ErrorGuaranteed>>::{closure#1} as core[f4906066c81ab25f]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  51:     0x7f4bd00bf783 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h255d5b0757ca4703
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/alloc/src/boxed.rs:1988:9
  52:     0x7f4bd00bf783 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h93c5eec9856fe0a3
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/alloc/src/boxed.rs:1988:9
  53:     0x7f4bd00bf783 - std::sys::unix::thread::Thread::new::thread_start::h28a60d678ab940df
                               at /rustc/511364e7874dba9649a264100407e4bffe7b5425/library/std/src/sys/unix/thread.rs:108:17
  54:     0x7f4bcfe29ff2 - start_thread
  55:     0x7f4bcfeacbfc - clone3
  56:                0x0 - <unknown>

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 1.70.0-nightly (511364e78 2023-03-16) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib

query stack during panic:
#0 [typeck] type-checking `<impl at melted.rs:4:1: 4:27>::deref`
#1 [type_of] computing type of `ReturnType::{opaque#0}`
#2 [check_mod_item_types] checking item types in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

@rustbot label +S-bug-has-mcve +F-type_alias_impl_trait

[matthiaskrgr]

Regression in nightly-2022-07-01

reproduced based of a modifiction of #88431 which does not need any feature gates and crashes stable:

use std::pin::Pin;

struct GameStateManager<'a> {
    gamestate_stack: Vec<Box<dyn GameState<'a> + 'a>>,
}

pub trait GameState<'a> {}

type FutureGameState<'a, 'b> = Pin<Box<impl for<'b> Fn() -> FutureGameState<'a, 'b> + 'a>>;

pub async fn get_replay_menu<'a>(
) -> Box<dyn for<'b> Fn(&'b mut GameStateManager<'a>) -> FutureGameState<'a, 'b> + 'a> {
    todo!()
}

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-medium