ICE: assertion failed: unique

[matthiaskrgr]

auto-reduced (treereduce-rust):

#![feature(return_position_impl_trait_in_trait, return_type_notation)]

trait IntFactory {
    fn stream(&self) -> impl IntFactory<stream(): IntFactory<stream(): Send> + Send>;
}

original:

#![feature(return_position_impl_trait_in_trait, return_type_notation)]

trait IntFactory {
    fn stream(&self) -> impl IntFactory<stream(): IntFactory<stream(): Send> + Send>;
}
trait SendIntFactory: IntFactory<stream(): Send> + Send {}

Version information

rustc 1.80.0-nightly (36c0a6d40 2024-05-18)
binary: rustc
commit-hash: 36c0a6d40fb6aae9c450305085d64e2ba55c6c58
commit-date: 2024-05-18
host: x86_64-unknown-linux-gnu
release: 1.80.0-nightly
LLVM version: 18.1.4

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc --crate-type=lib

Program output

warning: the feature `return_type_notation` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /tmp/icemaker_global_tempdir.m4kvtvaNzsSJ/rustc_testrunner_tmpdir_reporting.sI91r3JGKfet/mvce.rs:1:49
  |
1 | #![feature(return_position_impl_trait_in_trait, return_type_notation)]
  |                                                 ^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #109417 <https://github.com/rust-lang/rust/issues/109417> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: the feature `return_position_impl_trait_in_trait` has been stable since 1.75.0 and no longer requires an attribute to enable
 --> /tmp/icemaker_global_tempdir.m4kvtvaNzsSJ/rustc_testrunner_tmpdir_reporting.sI91r3JGKfet/mvce.rs:1:12
  |
1 | #![feature(return_position_impl_trait_in_trait, return_type_notation)]
  |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(stable_features)]` on by default

warning: trait `IntFactory` is never used
 --> /tmp/icemaker_global_tempdir.m4kvtvaNzsSJ/rustc_testrunner_tmpdir_reporting.sI91r3JGKfet/mvce.rs:3:7
  |
3 | trait IntFactory {
  |       ^^^^^^^^^^
  |
  = note: `#[warn(dead_code)]` on by default

thread 'rustc' panicked at compiler/rustc_lint/src/impl_trait_overcaptures.rs:171:21:
assertion failed: unique
stack backtrace:
   0:     0x7e9f17fe69e5 - std::backtrace_rs::backtrace::libunwind::trace::hf2bc7f5038b3e369
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/../../backtrace/src/backtrace/libunwind.rs:105:5
   1:     0x7e9f17fe69e5 - std::backtrace_rs::backtrace::trace_unsynchronized::h231bca9ebdb2d476
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7e9f17fe69e5 - std::sys_common::backtrace::_print_fmt::hb8880a770a528751
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7e9f17fe69e5 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h33a25d9d3cddcff1
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7e9f18035b9b - core::fmt::rt::Argument::fmt::hb79968a3099c2b80
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/core/src/fmt/rt.rs:165:63
   5:     0x7e9f18035b9b - core::fmt::write::h87de2705f4fdde46
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/core/src/fmt/mod.rs:1169:21
   6:     0x7e9f17fdb77f - std::io::Write::write_fmt::habafebc10fded2ab
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/io/mod.rs:1835:15
   7:     0x7e9f17fe67be - std::sys_common::backtrace::_print::hb1d61293da984960
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7e9f17fe67be - std::sys_common::backtrace::print::h2131b88f8087e7b2
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7e9f17fe91b9 - std::panicking::default_hook::{{closure}}::h68cf6ae540909963
  10:     0x7e9f17fe8efd - std::panicking::default_hook::h4b57c10c74892259
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/panicking.rs:298:9
  11:     0x7e9f148fba8f - std[4409b2d227107481]::panicking::update_hook::<alloc[62996783038b3a10]::boxed::Box<rustc_driver_impl[ec6cf89b952751b7]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7e9f17fe98eb - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hf3d7594c845607a3
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/alloc/src/boxed.rs:2036:9
  13:     0x7e9f17fe98eb - std::panicking::rust_panic_with_hook::he223310e59b58621
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/panicking.rs:799:13
  14:     0x7e9f17fe962b - std::panicking::begin_panic_handler::{{closure}}::h2b1c193a81afbc45
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/panicking.rs:656:13
  15:     0x7e9f17fe6ea9 - std::sys_common::backtrace::__rust_end_short_backtrace::h4f10616ff00feb98
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7e9f17fe9397 - rust_begin_unwind
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/panicking.rs:652:5
  17:     0x7e9f18032163 - core::panicking::panic_fmt::hcc56f9541c31fe59
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/core/src/panicking.rs:72:14
  18:     0x7e9f1803220c - core::panicking::panic::h5c79f86ebaa4ce23
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/core/src/panicking.rs:146:5
  19:     0x7e9f1634d56c - <rustc_lint[18589ef7f21dc6df]::impl_trait_overcaptures::VisitOpaqueTypes as rustc_type_ir[fcc5e9d53e164095]::visit::TypeVisitor<rustc_middle[94c1eba9c157edd1]::ty::context::TyCtxt>>::visit_ty
  20:     0x7e9f1634cf09 - <rustc_lint[18589ef7f21dc6df]::impl_trait_overcaptures::VisitOpaqueTypes as rustc_type_ir[fcc5e9d53e164095]::visit::TypeVisitor<rustc_middle[94c1eba9c157edd1]::ty::context::TyCtxt>>::visit_ty
  21:     0x7e9f1634bda6 - <rustc_lint[18589ef7f21dc6df]::impl_trait_overcaptures::VisitOpaqueTypes as rustc_type_ir[fcc5e9d53e164095]::visit::TypeVisitor<rustc_middle[94c1eba9c157edd1]::ty::context::TyCtxt>>::visit_binder::<rustc_type_ir[fcc5e9d53e164095]::ty_kind::FnSig<rustc_middle[94c1eba9c157edd1]::ty::context::TyCtxt>>
  22:     0x7e9f1634b18c - rustc_lint[18589ef7f21dc6df]::impl_trait_overcaptures::check_fn
  23:     0x7e9f15e7c4b8 - <rustc_lint[18589ef7f21dc6df]::late::LateContextAndPass<rustc_lint[18589ef7f21dc6df]::BuiltinCombinedModuleLateLintPass> as rustc_hir[38c888bf6a6f703]::intravisit::Visitor>::visit_nested_item
  24:     0x7e9f15e7ab29 - rustc_lint[18589ef7f21dc6df]::lint_mod
  25:     0x7e9f15e7a921 - rustc_query_impl[98154bf48ac5ed09]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[98154bf48ac5ed09]::query_impl::lint_mod::dynamic_query::{closure#2}::{closure#0}, rustc_middle[94c1eba9c157edd1]::query::erase::Erased<[u8; 0usize]>>
  26:     0x7e9f1674297d - rustc_query_system[8e8a87f940666368]::query::plumbing::try_execute_query::<rustc_query_impl[98154bf48ac5ed09]::DynamicConfig<rustc_query_system[8e8a87f940666368]::query::caches::DefaultCache<rustc_span[744739c6604e47db]::def_id::LocalModDefId, rustc_middle[94c1eba9c157edd1]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[98154bf48ac5ed09]::plumbing::QueryCtxt, false>
  27:     0x7e9f167407ff - rustc_query_impl[98154bf48ac5ed09]::query_impl::lint_mod::get_query_non_incr::__rust_end_short_backtrace
  28:     0x7e9f167403d9 - rustc_lint[18589ef7f21dc6df]::late::check_crate::{closure#1}
  29:     0x7e9f1673fe00 - rustc_lint[18589ef7f21dc6df]::late::check_crate
  30:     0x7e9f16749453 - rustc_interface[ada677875731fed0]::passes::analysis
  31:     0x7e9f1674895b - rustc_query_impl[98154bf48ac5ed09]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[98154bf48ac5ed09]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[94c1eba9c157edd1]::query::erase::Erased<[u8; 1usize]>>
  32:     0x7e9f169abee5 - rustc_query_system[8e8a87f940666368]::query::plumbing::try_execute_query::<rustc_query_impl[98154bf48ac5ed09]::DynamicConfig<rustc_query_system[8e8a87f940666368]::query::caches::SingleCache<rustc_middle[94c1eba9c157edd1]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[98154bf48ac5ed09]::plumbing::QueryCtxt, false>
  33:     0x7e9f169abc49 - rustc_query_impl[98154bf48ac5ed09]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  34:     0x7e9f16822fce - rustc_interface[ada677875731fed0]::interface::run_compiler::<core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>, rustc_driver_impl[ec6cf89b952751b7]::run_compiler::{closure#0}>::{closure#1}
  35:     0x7e9f1680da49 - std[4409b2d227107481]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[ada677875731fed0]::util::run_in_thread_with_globals<rustc_interface[ada677875731fed0]::util::run_in_thread_pool_with_globals<rustc_interface[ada677875731fed0]::interface::run_compiler<core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>, rustc_driver_impl[ec6cf89b952751b7]::run_compiler::{closure#0}>::{closure#1}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>::{closure#0}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>
  36:     0x7e9f1680d7f6 - <<std[4409b2d227107481]::thread::Builder>::spawn_unchecked_<rustc_interface[ada677875731fed0]::util::run_in_thread_with_globals<rustc_interface[ada677875731fed0]::util::run_in_thread_pool_with_globals<rustc_interface[ada677875731fed0]::interface::run_compiler<core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>, rustc_driver_impl[ec6cf89b952751b7]::run_compiler::{closure#0}>::{closure#1}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>::{closure#0}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[b65be67b0b9d2881]::result::Result<(), rustc_span[744739c6604e47db]::ErrorGuaranteed>>::{closure#2} as core[b65be67b0b9d2881]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  37:     0x7e9f17ff378b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd707e428c387a32b
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/alloc/src/boxed.rs:2022:9
  38:     0x7e9f17ff378b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h5849656bb97cf604
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/alloc/src/boxed.rs:2022:9
  39:     0x7e9f17ff378b - std::sys::pal::unix::thread::Thread::new::thread_start::h493d13a7185ac4a0
                               at /rustc/36c0a6d40fb6aae9c450305085d64e2ba55c6c58/library/std/src/sys/pal/unix/thread.rs:108:17
  40:     0x7e9f17d9255a - <unknown>
  41:     0x7e9f17e0fa3c - <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: please make sure that you have updated to the latest nightly

note: rustc 1.80.0-nightly (36c0a6d40 2024-05-18) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -Z dump-mir-dir=dir

query stack during panic:
#0 [lint_mod] linting top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
warning: 3 warnings emitted

@rustbot label +F-return_position_impl_trait_in_trait +F-return_type_notation

[matthiaskrgr]

Regression in nightly-2024-05-15
#124228 cc @compiler-errors