ICE: index out of bounds: the len is 323 but the index is 324, ena-0.14.0/src/snapshot_vec.rs:199:10

[jyn514]

Code

This was in a closed source codebase I don't have time to minimize right now. It happened when I called .unwrap_or_else() (or something like that, don't exactly remember) on a value with type impl Future<Output = Result<T, E>>. Don't remember what T or E were :(

Meta

rustc --version --verbose:

rustc 1.64.0-nightly (2643b1646 2022-07-27)

Error output

thread 'rustc' panicked at 'index out of bounds: the len is 323 but the index is 324', /cargo/registry/src/github.com-1ecc6299db9ec823/ena-0.14.0/src/snapshot_vec.rs:199:10

Backtrace

thread 'rustc' panicked at 'index out of bounds: the len is 323 but the index is 324', /cargo/registry/src/github.com-1ecc6299db9ec823/ena-0.14.0/src/snapshot_vec.rs:199:10
stack backtrace:
   0:     0x7fb84c72a2f0 - std::backtrace_rs::backtrace::libunwind::trace::hfde61216c3eb9aa2
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   1:     0x7fb84c72a2f0 - std::backtrace_rs::backtrace::trace_unsynchronized::h0b75016d6e62613e
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb84c72a2f0 - std::sys_common::backtrace::_print_fmt::hb881989378b0427a
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7fb84c72a2f0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd3d0d57171db7305
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7fb84c78570c - core::fmt::write::h27d3752df3a82c58
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/core/src/fmt/mod.rs:1198:17
   5:     0x7fb84c71b325 - std::io::Write::write_fmt::h5c80c98739fc77ee
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/io/mod.rs:1672:15
   6:     0x7fb84c72cfc1 - std::sys_common::backtrace::_print::haae4b9f0159881ee
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7fb84c72cfc1 - std::sys_common::backtrace::print::h2ee3dba2d51e8a7c
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7fb84c72cfc1 - std::panicking::default_hook::{{closure}}::h1b241d9ed5d4bf62
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/panicking.rs:295:22
   9:     0x7fb84c72cc93 - std::panicking::default_hook::hbfcb9dc844ea015d
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/panicking.rs:314:9
  10:     0x7fb84ef01114 - rustc_driver[65b554bd076cf949]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7fb84c72d7f6 - std::panicking::rust_panic_with_hook::ha922eb0926dfacd1
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/panicking.rs:702:17
  12:     0x7fb84c72d647 - std::panicking::begin_panic_handler::{{closure}}::h755221379ec8b759
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/panicking.rs:588:13
  13:     0x7fb84c72a814 - std::sys_common::backtrace::__rust_end_short_backtrace::hdaef891366623f57
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys_common/backtrace.rs:138:18
  14:     0x7fb84c72d372 - rust_begin_unwind
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/panicking.rs:584:5
  15:     0x7fb84c7821e3 - core::panicking::panic_fmt::hb3e01db1bb39d23b
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/core/src/panicking.rs:142:14
  16:     0x7fb84c782122 - core::panicking::panic_bounds_check::hfa135c33a77c9e3c
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/core/src/panicking.rs:84:5
  17:     0x7fb84d8502db - <&rustc_middle[bd19c556bfbde64d]::ty::list::List<rustc_middle[bd19c556bfbde64d]::ty::subst::GenericArg> as rustc_middle[bd19c556bfbde64d]::ty::fold::TypeFoldable>::try_fold_with::<rustc_infer[9fb44eec1c8d58c7]::infer::resolve::OpportunisticVarResolver>
  18:     0x7fb84d84f10d - <rustc_infer[9fb44eec1c8d58c7]::infer::resolve::OpportunisticVarResolver as rustc_middle[bd19c556bfbde64d]::ty::fold::FallibleTypeFolder>::try_fold_ty
  19:     0x7fb84fd4e7d6 - <(rustc_middle[bd19c556bfbde64d]::ty::Ty, rustc_middle[bd19c556bfbde64d]::ty::Ty) as rustc_middle[bd19c556bfbde64d]::ty::fold::TypeFoldable>::fold_with::<rustc_infer[9fb44eec1c8d58c7]::infer::resolve::OpportunisticVarResolver>
  20:     0x7fb84fd4153f - <rustc_infer[9fb44eec1c8d58c7]::infer::InferCtxt>::same_type_modulo_infer
  21:     0x7fb84fd46ab2 - <rustc_infer[9fb44eec1c8d58c7]::infer::InferCtxt>::note_type_err
  22:     0x7fb84fd3d3c7 - <rustc_infer[9fb44eec1c8d58c7]::infer::InferCtxt>::report_and_explain_type_error
  23:     0x7fb84da7d44b - <rustc_infer[9fb44eec1c8d58c7]::infer::InferCtxt>::report_mismatched_types
  24:     0x7fb84f350641 - <rustc_typeck[664e6494d36bc9f9]::check::coercion::CoerceMany<&rustc_hir[e63fe2e2ba61df9e]::hir::Expr>>::report_return_mismatched_types
  25:     0x7fb84da40ad5 - <rustc_typeck[664e6494d36bc9f9]::check::coercion::CoerceMany<&rustc_hir[e63fe2e2ba61df9e]::hir::Expr>>::coerce
  26:     0x7fb84dd75752 - rustc_typeck[664e6494d36bc9f9]::check::check::check_fn
  27:     0x7fb84daa087a - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_closure
  28:     0x7fb84da347a3 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  29:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  30:     0x7fb84da3304c - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  31:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  32:     0x7fb84d9e5b7e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_call
  33:     0x7fb84da31b69 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  34:     0x7fb84da704ac - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_match
  35:     0x7fb84da33244 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  36:     0x7fb84da659a1 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_decl
  37:     0x7fb84da3527b - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  38:     0x7fb84da334cc - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  39:     0x7fb84da4423e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_block_with_expected
  40:     0x7fb84da31c96 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  41:     0x7fb84dd7566e - rustc_typeck[664e6494d36bc9f9]::check::check::check_fn
  42:     0x7fb84daa087a - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_closure
  43:     0x7fb84da347a3 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  44:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  45:     0x7fb84d9e5b7e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_call
  46:     0x7fb84da31b69 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  47:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  48:     0x7fb84d9e5b7e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_call
  49:     0x7fb84da31b69 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  50:     0x7fb84da44033 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_block_with_expected
  51:     0x7fb84da31c96 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  52:     0x7fb84dd7566e - rustc_typeck[664e6494d36bc9f9]::check::check::check_fn
  53:     0x7fb84daa087a - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_closure
  54:     0x7fb84da347a3 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  55:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  56:     0x7fb84da3304c - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  57:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  58:     0x7fb84d9e5b7e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_call
  59:     0x7fb84da31b69 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  60:     0x7fb84da704ac - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_match
  61:     0x7fb84da33244 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  62:     0x7fb84da4423e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_block_with_expected
  63:     0x7fb84da31c96 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  64:     0x7fb84da337a8 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  65:     0x7fb84da4423e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_block_with_expected
  66:     0x7fb84da31c96 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  67:     0x7fb84dd7566e - rustc_typeck[664e6494d36bc9f9]::check::check::check_fn
  68:     0x7fb84daa087a - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_closure
  69:     0x7fb84da347a3 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  70:     0x7fb84da2bd3f - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_argument_types
  71:     0x7fb84d9e5b7e - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_call
  72:     0x7fb84da31b69 - <rustc_typeck[664e6494d36bc9f9]::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  73:     0x7fb84dd7566e - rustc_typeck[664e6494d36bc9f9]::check::check::check_fn
  74:     0x7fb84dd63147 - <rustc_infer[9fb44eec1c8d58c7]::infer::InferCtxtBuilder>::enter::<&rustc_middle[bd19c556bfbde64d]::ty::context::TypeckResults, <rustc_typeck[664e6494d36bc9f9]::check::inherited::InheritedBuilder>::enter<rustc_typeck[664e6494d36bc9f9]::check::typeck_with_fallback<rustc_typeck[664e6494d36bc9f9]::check::typeck::{closure#0}>::{closure#1}, &rustc_middle[bd19c556bfbde64d]::ty::context::TypeckResults>::{closure#0}>
  75:     0x7fb84e926ec6 - rustc_typeck[664e6494d36bc9f9]::check::typeck
  76:     0x7fb84e53406f - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[bd19c556bfbde64d]::ty::context::TyCtxt, rustc_span[c9cc50052627be11]::def_id::LocalDefId, &rustc_middle[bd19c556bfbde64d]::ty::context::TypeckResults>
  77:     0x7fb84e52c40a - rustc_query_system[8afb442a6454b51e]::query::plumbing::try_execute_query::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt, rustc_query_system[8afb442a6454b51e]::query::caches::DefaultCache<rustc_span[c9cc50052627be11]::def_id::LocalDefId, &rustc_middle[bd19c556bfbde64d]::ty::context::TypeckResults>>
  78:     0x7fb84eb6eff6 - rustc_query_system[8afb442a6454b51e]::query::plumbing::force_query::<rustc_query_impl[7b7d1ce597391f7c]::queries::typeck, rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  79:     0x7fb84eb6ee3e - rustc_query_impl[7b7d1ce597391f7c]::query_callbacks::typeck::force_from_dep_node
  80:     0x7fb84d97bfe1 - <rustc_middle[bd19c556bfbde64d]::ty::context::TyCtxt as rustc_query_system[8afb442a6454b51e]::dep_graph::DepContext>::try_force_from_dep_node
  81:     0x7fb84d97b54a - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  82:     0x7fb84d97adc6 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  83:     0x7fb84d97adc6 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  84:     0x7fb84d97adc6 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  85:     0x7fb84d97adc6 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  86:     0x7fb84d97adc6 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  87:     0x7fb84e3846e7 - rustc_query_system[8afb442a6454b51e]::query::plumbing::get_query::<rustc_query_impl[7b7d1ce597391f7c]::queries::type_of, rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  88:     0x7fb84e828b98 - rustc_typeck[664e6494d36bc9f9]::check::check::check_item_type
  89:     0x7fb84e82505e - rustc_typeck[664e6494d36bc9f9]::check::check::check_mod_item_types
  90:     0x7fb84e1f5642 - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[bd19c556bfbde64d]::ty::context::TyCtxt, rustc_span[c9cc50052627be11]::def_id::LocalDefId, ()>
  91:     0x7fb84e1f47ce - rustc_query_system[8afb442a6454b51e]::query::plumbing::try_execute_query::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt, rustc_query_system[8afb442a6454b51e]::query::caches::DefaultCache<rustc_span[c9cc50052627be11]::def_id::LocalDefId, ()>>
  92:     0x7fb84e96df43 - rustc_query_system[8afb442a6454b51e]::query::plumbing::get_query::<rustc_query_impl[7b7d1ce597391f7c]::queries::check_mod_item_types, rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  93:     0x7fb84ec0e0ef - <rustc_middle[bd19c556bfbde64d]::hir::map::Map>::for_each_module::<rustc_typeck[664e6494d36bc9f9]::check_crate::{closure#6}::{closure#0}>
  94:     0x7fb84e8eb795 - rustc_typeck[664e6494d36bc9f9]::check_crate
  95:     0x7fb84e8ead67 - rustc_interface[6c4ed5f5bcefca51]::passes::analysis
  96:     0x7fb84ecc273c - <rustc_query_system[8afb442a6454b51e]::dep_graph::graph::DepGraph<rustc_middle[bd19c556bfbde64d]::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle[bd19c556bfbde64d]::ty::context::TyCtxt, (), core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>
  97:     0x7fb84ecc1efb - rustc_query_system[8afb442a6454b51e]::query::plumbing::try_execute_query::<rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt, rustc_query_system[8afb442a6454b51e]::query::caches::DefaultCache<(), core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>>
  98:     0x7fb84ecc1a4e - rustc_query_system[8afb442a6454b51e]::query::plumbing::get_query::<rustc_query_impl[7b7d1ce597391f7c]::queries::analysis, rustc_query_impl[7b7d1ce597391f7c]::plumbing::QueryCtxt>
  99:     0x7fb84e68ec5e - <rustc_interface[6c4ed5f5bcefca51]::passes::QueryContext>::enter::<rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>
 100:     0x7fb84e68908e - <rustc_interface[6c4ed5f5bcefca51]::interface::Compiler>::enter::<rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}::{closure#2}, core[985efce893a97efa]::result::Result<core[985efce893a97efa]::option::Option<rustc_interface[6c4ed5f5bcefca51]::queries::Linker>, rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>
 101:     0x7fb84e6849da - rustc_span[c9cc50052627be11]::with_source_map::<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_interface[6c4ed5f5bcefca51]::interface::create_compiler_and_run<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}>::{closure#1}>
 102:     0x7fb84e684430 - rustc_interface[6c4ed5f5bcefca51]::interface::create_compiler_and_run::<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}>
 103:     0x7fb84e6826e2 - <scoped_tls[c96fdd959bf6d57b]::ScopedKey<rustc_span[c9cc50052627be11]::SessionGlobals>>::set::<rustc_interface[6c4ed5f5bcefca51]::interface::run_compiler<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}>::{closure#0}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>
 104:     0x7fb84e6823cf - std[7b29f0aeec6d7a3b]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[6c4ed5f5bcefca51]::util::run_in_thread_pool_with_globals<rustc_interface[6c4ed5f5bcefca51]::interface::run_compiler<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}>::{closure#0}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>::{closure#0}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>
 105:     0x7fb84ed3f239 - <<std[7b29f0aeec6d7a3b]::thread::Builder>::spawn_unchecked_<rustc_interface[6c4ed5f5bcefca51]::util::run_in_thread_pool_with_globals<rustc_interface[6c4ed5f5bcefca51]::interface::run_compiler<core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>, rustc_driver[65b554bd076cf949]::run_compiler::{closure#1}>::{closure#0}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>::{closure#0}, core[985efce893a97efa]::result::Result<(), rustc_errors[4b4dc7f65bce4740]::ErrorGuaranteed>>::{closure#1} as core[985efce893a97efa]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
 106:     0x7fb84c737293 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h5b4844b306fb76ba
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/alloc/src/boxed.rs:1935:9
 107:     0x7fb84c737293 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h90126c2a440b419a
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/alloc/src/boxed.rs:1935:9
 108:     0x7fb84c737293 - std::sys::unix::thread::Thread::new::thread_start::hfc37efb2513bd228
                               at /rustc/2643b16468fda787470340890212591d8bc832b7/library/std/src/sys/unix/thread.rs:108:17
 109:     0x7fb84c5f0609 - start_thread
                               at /build/glibc-SzIz7B/glibc-2.31/nptl/pthread_create.c:477:8
 110:     0x7fb84c513133 - clone
                               at /build/glibc-SzIz7B/glibc-2.31/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95
 111:                0x0 - <unknown>

error: internal compiler error: unexpected panic

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 1.64.0-nightly (2643b1646 2022-07-27) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type lib -C embed-bitcode=no -C debuginfo=2 -C incremental

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

query stack during panic:
#0 [typeck] type-checking `endpoints::serve::serve_udp`
#1 [type_of] computing type of `endpoints::serve::serve_udp::{opaque#0}`
#2 [check_mod_item_types] checking item types in module `endpoints::serve`
#3 [analysis] running analysis passes on this crate
end of query stack

[matthiaskrgr]

might be related to one of these ^^
https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+src%2Fsnapshot_vec.rs

[compiler-errors]

Ugh, this is due to adding this InferCtxt::resolve_vars_if_possible call -- something is calling this InferCtxt::same_type_modulo_infer with a type that has region variables that no longer exist, probably from an InferCtxt::probe or InferCtxt::commit_if_ok...

I can possibly try to reproduce, but this will be difficult to do without an MVCE.

[matthiaskrgr]

@compiler-errors can you try rustc ./src/test/ui/hrtb/issue-95034.rs --edition=2021 --crate-type lib or is this a different issue?

[compiler-errors]

This is a different issue. #95034 is a trait solver issue having to do with higher ranked type equality and the Generalizer.

This has to do with a region variable escaping out of a InferCtxt::commit_if_ok. Specifically it's this one: https://doc.rust-lang.org/nightly/nightly-rustc/src/rustc_typeck/check/coercion.rs.html#944

[compiler-errors]

Actually wait this is a type variable that's escaping. Ugh, probably due to opaque types :?

[jyn514]

oh I forgot I saved this code

I will try to trim it down to something I can post publicly

[compiler-errors]

@jyn514 if you can, it would be incredibly useful here.

[jyn514]

@compiler-errors

struct Error;

fn foo() {
    let initial_exchange: Result<usize, Error> = todo!();
    initial_exchange.and_then(|_|
        serve_udp_tunnel()
    ).await;
}

async fn serve_udp_tunnel() {}

query stack during panic:
#0 [typeck] type-checking `foo`
#1 [typeck_item_bodies] type-checking all item bodies
#2 [analysis] running analysis passes on this crate
end of query stack