ICE: escaping late-bound region during canonicalization with lifetime-generic TAIT

[Jules-Bertholet]

Code

#![feature(type_alias_impl_trait)]

type Tait<'b> = impl Sized;

fn foo(f: &dyn Fn(Tait)) {}

Meta

Version:

1.66.0-nightly
(2022-10-26 1898c34e923bad763e72)

Error output

error: internal compiler error: compiler/rustc_infer/src/infer/canonical/canonicalizer.rs:351:21: escaping late-bound region during canonicalization

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/compiler/rustc_errors/src/lib.rs:1519:9
stack backtrace:
   0:     0x7f76f6c6a160 - std::backtrace_rs::backtrace::libunwind::trace::h335cb7d284210dcd
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   1:     0x7f76f6c6a160 - std::backtrace_rs::backtrace::trace_unsynchronized::h96bebe31884696aa
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f76f6c6a160 - std::sys_common::backtrace::_print_fmt::h3a966776806a5901
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f76f6c6a160 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h9873151158634bfb
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f76f2ded7ae - core::fmt::write::h76f1dd707576780a
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/core/src/fmt/mod.rs:1209:17
   5:     0x7f76f6c5de15 - std::io::Write::write_fmt::h92487d1ebc53913c
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/io/mod.rs:1682:15
   6:     0x7f76f6c69f25 - std::sys_common::backtrace::_print::hb4e235864fa298b0
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7f76f6c69f25 - std::sys_common::backtrace::print::h653f44b23a413cb5
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7f76f6c6c27f - std::panicking::default_hook::{{closure}}::hc9092a79fd9e0703
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/panicking.rs:267:22
   9:     0x7f76f6c6bfba - std::panicking::default_hook::h2a487c86ebeb8ba4
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/panicking.rs:286:9
  10:     0x7f76f5f2be64 - <rustc_driver[3a9e58a752c57e0a]::DEFAULT_HOOK::{closure#0}::{closure#0} as core[731c476bbe2eb77e]::ops::function::FnOnce<(&core[731c476bbe2eb77e]::panic::panic_info::PanicInfo,)>>::call_once::{shim:vtable#0}
  11:     0x7f76f6c6ca69 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hcab349cf6232f449
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/alloc/src/boxed.rs:2001:9
  12:     0x7f76f6c6ca69 - std::panicking::rust_panic_with_hook::hb9a0a3528b1a00c5
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/panicking.rs:692:13
  13:     0x7f76f63c1891 - std[fe5f4c1edace479]::panicking::begin_panic::<rustc_errors[a667d3b760aec769]::ExplicitBug>::{closure#0}
  14:     0x7f76f63be386 - std[fe5f4c1edace479]::sys_common::backtrace::__rust_end_short_backtrace::<std[fe5f4c1edace479]::panicking::begin_panic<rustc_errors[a667d3b760aec769]::ExplicitBug>::{closure#0}, !>
  15:     0x7f76f63bcfa6 - std[fe5f4c1edace479]::panicking::begin_panic::<rustc_errors[a667d3b760aec769]::ExplicitBug>
  16:     0x7f76f63551f6 - std[fe5f4c1edace479]::panic::panic_any::<rustc_errors[a667d3b760aec769]::ExplicitBug>
  17:     0x7f76f635510d - <rustc_errors[a667d3b760aec769]::HandlerInner>::bug::<&alloc[a0d4246b74acabb6]::string::String>
  18:     0x7f76f6354b80 - <rustc_errors[a667d3b760aec769]::Handler>::bug::<&alloc[a0d4246b74acabb6]::string::String>
  19:     0x7f76f6406985 - rustc_middle[25dd0db25d9b6162]::ty::context::tls::with_context_opt::<rustc_middle[25dd0db25d9b6162]::ty::context::tls::with_opt<rustc_middle[25dd0db25d9b6162]::util::bug::opt_span_bug_fmt<rustc_span[882156c2b67f5204]::span_encoding::Span>::{closure#0}, ()>::{closure#0}, ()>
  20:     0x7f76f6406cc6 - rustc_middle[25dd0db25d9b6162]::util::bug::opt_span_bug_fmt::<rustc_span[882156c2b67f5204]::span_encoding::Span>
  21:     0x7f76f41bba93 - rustc_middle[25dd0db25d9b6162]::util::bug::bug_fmt
  22:     0x7f76f40a319e - <rustc_infer[84debb9d2c0822d1]::infer::canonical::canonicalizer::Canonicalizer as rustc_middle[25dd0db25d9b6162]::ty::fold::TypeFolder>::fold_region
  23:     0x7f76f5182f69 - <&rustc_middle[25dd0db25d9b6162]::ty::list::List<rustc_middle[25dd0db25d9b6162]::ty::subst::GenericArg> as rustc_middle[25dd0db25d9b6162]::ty::fold::TypeFoldable>::try_fold_with::<rustc_infer[84debb9d2c0822d1]::infer::canonical::canonicalizer::Canonicalizer>
  24:     0x7f76f51607f0 - <rustc_middle[25dd0db25d9b6162]::infer::canonical::QueryResponse<alloc[a0d4246b74acabb6]::vec::Vec<rustc_middle[25dd0db25d9b6162]::traits::query::OutlivesBound>> as rustc_middle[25dd0db25d9b6162]::ty::fold::TypeFoldable>::fold_with::<rustc_infer[84debb9d2c0822d1]::infer::canonical::canonicalizer::Canonicalizer>
  25:     0x7f76f4c9dc6f - <rustc_infer[84debb9d2c0822d1]::infer::InferCtxtBuilder as rustc_trait_selection[7f17b2023115ca83]::infer::InferCtxtBuilderExt>::enter_canonical_trait_query::<rustc_middle[25dd0db25d9b6162]::ty::ParamEnvAnd<rustc_middle[25dd0db25d9b6162]::ty::Ty>, alloc[a0d4246b74acabb6]::vec::Vec<rustc_middle[25dd0db25d9b6162]::traits::query::OutlivesBound>, rustc_traits[1f9741b68d8bb0df]::implied_outlives_bounds::implied_outlives_bounds::{closure#0}>
  26:     0x7f76f50e1530 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::try_execute_query::<rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt, rustc_query_system[2ce74b9538bccb8f]::query::caches::DefaultCache<rustc_middle[25dd0db25d9b6162]::infer::canonical::Canonical<rustc_middle[25dd0db25d9b6162]::ty::ParamEnvAnd<rustc_middle[25dd0db25d9b6162]::ty::Ty>>, core[731c476bbe2eb77e]::result::Result<&rustc_middle[25dd0db25d9b6162]::infer::canonical::Canonical<rustc_middle[25dd0db25d9b6162]::infer::canonical::QueryResponse<alloc[a0d4246b74acabb6]::vec::Vec<rustc_middle[25dd0db25d9b6162]::traits::query::OutlivesBound>>>, rustc_middle[25dd0db25d9b6162]::traits::query::NoSolution>>>
  27:     0x7f76f4533cb9 - <rustc_trait_selection[7f17b2023115ca83]::traits::query::type_op::implied_outlives_bounds::ImpliedOutlivesBounds as rustc_trait_selection[7f17b2023115ca83]::traits::query::type_op::QueryTypeOp>::fully_perform_into
  28:     0x7f76f4c382c2 - <rustc_infer[84debb9d2c0822d1]::infer::outlives::env::OutlivesEnvironment>::with_bounds::<core[731c476bbe2eb77e]::iter::adapters::flatten::Flatten<core[731c476bbe2eb77e]::iter::adapters::map::Map<std[fe5f4c1edace479]::collections::hash::set::IntoIter<rustc_middle[25dd0db25d9b6162]::ty::Ty>, <rustc_infer[84debb9d2c0822d1]::infer::InferCtxt as rustc_trait_selection[7f17b2023115ca83]::traits::outlives_bounds::InferCtxtExt>::implied_bounds_tys::{closure#0}>>>
  29:     0x7f76f4c317b3 - rustc_hir_analysis[365bb067b141719f]::check::wfcheck::check_item_fn
  30:     0x7f76f4c29306 - rustc_hir_analysis[365bb067b141719f]::check::wfcheck::check_well_formed
  31:     0x7f76f415f5f5 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::get_query::<rustc_query_impl[1922eb72fec2b651]::queries::check_well_formed, rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt>
  32:     0x7f76f5428d09 - rustc_data_structures[a2db8ee2a835d2c8]::sync::par_for_each_in::<&[rustc_hir[12b882f0377fe91d]::hir::ItemId], <rustc_middle[25dd0db25d9b6162]::hir::ModuleItems>::par_items<rustc_hir_analysis[365bb067b141719f]::check::wfcheck::check_mod_type_wf::{closure#0}>::{closure#0}>
  33:     0x7f76f586d161 - rustc_hir_analysis[365bb067b141719f]::check::wfcheck::check_mod_type_wf
  34:     0x7f76f47f2878 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::try_execute_query::<rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt, rustc_query_system[2ce74b9538bccb8f]::query::caches::DefaultCache<rustc_span[882156c2b67f5204]::def_id::LocalDefId, ()>>
  35:     0x7f76f53b3f79 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::get_query::<rustc_query_impl[1922eb72fec2b651]::queries::check_mod_type_wf, rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt>
  36:     0x7f76f437b798 - rustc_data_structures[a2db8ee2a835d2c8]::sync::par_for_each_in::<&[rustc_hir[12b882f0377fe91d]::hir_id::OwnerId], <rustc_middle[25dd0db25d9b6162]::hir::map::Map>::par_for_each_module<rustc_hir_analysis[365bb067b141719f]::check_crate::{closure#5}::{closure#0}::{closure#0}>::{closure#0}>
  37:     0x7f76f437b5b3 - <rustc_session[918d7b2bbd2629cb]::session::Session>::track_errors::<rustc_hir_analysis[365bb067b141719f]::check_crate::{closure#5}, ()>
  38:     0x7f76f437ace1 - rustc_hir_analysis[365bb067b141719f]::check_crate
  39:     0x7f76f437a98b - rustc_interface[38d8e7298dc9bf29]::passes::analysis
  40:     0x7f76f576ef54 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::try_execute_query::<rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt, rustc_query_system[2ce74b9538bccb8f]::query::caches::DefaultCache<(), core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>>
  41:     0x7f76f576ec57 - rustc_query_system[2ce74b9538bccb8f]::query::plumbing::get_query::<rustc_query_impl[1922eb72fec2b651]::queries::analysis, rustc_query_impl[1922eb72fec2b651]::plumbing::QueryCtxt>
  42:     0x7f76f52a036d - <rustc_interface[38d8e7298dc9bf29]::passes::QueryContext>::enter::<rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>
  43:     0x7f76f529c92f - <rustc_interface[38d8e7298dc9bf29]::interface::Compiler>::enter::<rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}::{closure#2}, core[731c476bbe2eb77e]::result::Result<core[731c476bbe2eb77e]::option::Option<rustc_interface[38d8e7298dc9bf29]::queries::Linker>, rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>
  44:     0x7f76f5294472 - rustc_span[882156c2b67f5204]::with_source_map::<core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>, rustc_interface[38d8e7298dc9bf29]::interface::run_compiler<core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>, rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}>::{closure#0}::{closure#1}>
  45:     0x7f76f5293f69 - <scoped_tls[f319009629b0a1b4]::ScopedKey<rustc_span[882156c2b67f5204]::SessionGlobals>>::set::<rustc_interface[38d8e7298dc9bf29]::interface::run_compiler<core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>, rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}>::{closure#0}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>
  46:     0x7f76f5293578 - std[fe5f4c1edace479]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[38d8e7298dc9bf29]::util::run_in_thread_pool_with_globals<rustc_interface[38d8e7298dc9bf29]::interface::run_compiler<core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>, rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}>::{closure#0}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>
  47:     0x7f76f529329c - <<std[fe5f4c1edace479]::thread::Builder>::spawn_unchecked_<rustc_interface[38d8e7298dc9bf29]::util::run_in_thread_pool_with_globals<rustc_interface[38d8e7298dc9bf29]::interface::run_compiler<core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>, rustc_driver[3a9e58a752c57e0a]::run_compiler::{closure#1}>::{closure#0}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[731c476bbe2eb77e]::result::Result<(), rustc_errors[a667d3b760aec769]::ErrorGuaranteed>>::{closure#1} as core[731c476bbe2eb77e]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  48:     0x7f76f6c739d3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h5b00bc9defbef88c
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/alloc/src/boxed.rs:1987:9
  49:     0x7f76f6c739d3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hc3b726dad8143273
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/alloc/src/boxed.rs:1987:9
  50:     0x7f76f6c739d3 - std::sys::unix::thread::Thread::new::thread_start::hf9c71b7d57dac377
                               at /rustc/1898c34e923bad763e723c68dd9f23a09f9eb0fc/library/std/src/sys/unix/thread.rs:108:17
  51:     0x7f76f2c70609 - start_thread
  52:     0x7f76f2b93133 - clone
  53:                0x0 - <unknown>

note: 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 1.66.0-nightly (1898c34e9 2022-10-26) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

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

query stack during panic:
#0 [implied_outlives_bounds] computing implied outlives bounds for `&dyn for<'a> core::ops::function::Fn(Tait<'a>)`
#1 [check_well_formed] checking that `foo` is well-formed
#2 [check_mod_type_wf] checking that types are well-formed in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack

[Rageking8]

@rustbot label +F-type_alias_impl_trait

[Alexendoo]

Fixed by #106910