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[ICE]: "hir-typeck passed but Reborrow does not have a lifetime argument" #156307

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[ICE]: "hir-typeck passed but Reborrow does not have a lifetime argument"#156307
Labels
C-bugCategory: This is a bug.F-reborrow`#![feature(reborrow)]`; see #145612I-ICEIssue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️T-compilerRelevant to the compiler team, which will review and decide on the PR/issue.
@theemathas

Description

@theemathas
theemathas
opened on May 8, 2026

Code

#![feature(reborrow)]

use std::marker::Reborrow;

struct Thing;

impl<'a> Reborrow for Thing {}

fn foo(_: Thing) {}

fn main() {
    let x = Thing;
    foo(x);
}

Presumably started ICE-ing in #151753. cc @aapoalas

Meta

rustc --version --verbose:

rustc 1.97.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: aarch64-apple-darwin
release: 1.97.0-dev
LLVM version: 22.1.4

Compiled from the main branch at commit 63b1dfc.

Error output

error: implementing `Reborrow` does not allow multiple lifetimes or fields to be coerced
 --> src/main.rs:7:1
  |
7 | impl<'a> Reborrow for Thing {}
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:313:17: hir-typeck passed but Reborrow does not have a lifetime argument


thread 'rustc' (303882) panicked at compiler/rustc_borrowck/src/borrow_set.rs:313:17:
Box<dyn Any>
Backtrace 

stack backtrace:
   0: begin_panic<rustc_errors::ExplicitBug>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:761:5
   1: panic_any<rustc_errors::ExplicitBug>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panic.rs:260:5
   2: emit_producing_guarantee
             at /Users/timch/rust/compiler/rustc_errors/src/diagnostic.rs:58:9
   3: emit<rustc_errors::diagnostic::BugAbort>
             at /Users/timch/rust/compiler/rustc_errors/src/diagnostic.rs:1282:9
   4: bug<alloc::string::String>
             at /Users/timch/rust/compiler/rustc_errors/src/lib.rs:928:30
   5: {closure#0}<rustc_span::span_encoding::Span>
             at /Users/timch/rust/compiler/rustc_middle/src/util/bug.rs:39:48
   6: {closure#0}<rustc_middle::util::bug::opt_span_bug_fmt::{closure_env#0}<rustc_span::span_encoding::Span>, !>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context/tls.rs:109:23
   7: with_context_opt<rustc_middle::ty::context::tls::with_opt::{closure_env#0}<rustc_middle::util::bug::opt_span_bug_fmt::{closure_env#0}<rustc_span::span_encoding::Span>, !>, !>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context/tls.rs:75:18
   8: with_opt<rustc_middle::util::bug::opt_span_bug_fmt::{closure_env#0}<rustc_span::span_encoding::Span>, !>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context/tls.rs:107:5
   9: opt_span_bug_fmt<rustc_span::span_encoding::Span>
             at /Users/timch/rust/compiler/rustc_middle/src/util/bug.rs:33:5
  10: bug_fmt
             at /Users/timch/rust/compiler/rustc_middle/src/util/bug.rs:16:5
  11: visit_assign
             at /Users/timch/rust/compiler/rustc_borrowck/src/borrow_set.rs:313:17
  12: super_statement<rustc_borrowck::borrow_set::GatherBorrows>
             at /Users/timch/rust/compiler/rustc_middle/src/mir/visit.rs:423:30
  13: visit_statement<rustc_borrowck::borrow_set::GatherBorrows>
             at /Users/timch/rust/compiler/rustc_middle/src/mir/visit.rs:111:22
  14: super_basic_block_data<rustc_borrowck::borrow_set::GatherBorrows>
             at /Users/timch/rust/compiler/rustc_middle/src/mir/visit.rs:311:26
  15: visit_basic_block_data<rustc_borrowck::borrow_set::GatherBorrows>
             at /Users/timch/rust/compiler/rustc_middle/src/mir/visit.rs:88:22
  16: build
             at /Users/timch/rust/compiler/rustc_borrowck/src/borrow_set.rs:191:21
  17: borrowck_collect_region_constraints
             at /Users/timch/rust/compiler/rustc_borrowck/src/lib.rs:343:22
  18: do_mir_borrowck
             at /Users/timch/rust/compiler/rustc_borrowck/src/root_cx.rs:269:26
  19: mir_borrowck
             at /Users/timch/rust/compiler/rustc_borrowck/src/lib.rs:141:17
      [... omitted 28 frames ...]
  20: query_ensure_ok_or_done<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::ErasedData<[u8; 8]>, rustc_middle::dep_graph::graph::DepNodeIndex>>
             at /Users/timch/rust/compiler/rustc_middle/src/query/inner.rs:63:13
  21: mir_borrowck<rustc_span::def_id::LocalDefId>
             at /Users/timch/rust/compiler/rustc_middle/src/query/plumbing.rs:589:21
  22: {closure#0}
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1165:33
  23: {closure#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>
             at /Users/timch/rust/compiler/rustc_middle/src/hir/map.rs:338:79
  24: {closure#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:182:30
  25: call_once<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/core/src/panic/unwind_safe.rs:275:9
  26: do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>, ()>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:581:40
  27: catch_unwind<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:544:19
  28: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>, ()>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panic.rs:359:14
  29: run<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure#1}::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:23:9
  30: {closure#1}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:182:23
  31: for_each<rustc_span::def_id::LocalDefId, rustc_data_structures::sync::parallel::par_for_each_in::{closure#0}::{closure_env#1}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/core/src/slice/iter/macros.rs:301:21
  32: {closure#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:181:27
  33: parallel_guard<(), rustc_data_structures::sync::parallel::par_for_each_in::{closure_env#0}<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:39:15
  34: par_for_each_in<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], rustc_middle::hir::map::{impl#3}::par_hir_body_owners::{closure_env#0}<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>>
             at /Users/timch/rust/compiler/rustc_data_structures/src/sync/parallel.rs:176:5
  35: par_hir_body_owners<rustc_interface::passes::run_required_analyses::{closure#2}::{closure_env#0}>
             at /Users/timch/rust/compiler/rustc_middle/src/hir/map.rs:338:9
  36: {closure#2}
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1155:13
  37: run<(), rustc_interface::passes::run_required_analyses::{closure_env#2}>
             at /Users/timch/rust/compiler/rustc_data_structures/src/profiling.rs:845:9
  38: time<(), rustc_interface::passes::run_required_analyses::{closure_env#2}>
             at /Users/timch/rust/compiler/rustc_session/src/utils.rs:17:50
  39: run_required_analyses
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1154:10
  40: analysis
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1198:5
      [... omitted 28 frames ...]
  41: query_ensure_ok_or_done<rustc_middle::query::caches::SingleCache<rustc_middle::query::erase::ErasedData<[u8; 0]>>>
             at /Users/timch/rust/compiler/rustc_middle/src/query/inner.rs:63:13
  42: analysis
             at /Users/timch/rust/compiler/rustc_middle/src/query/plumbing.rs:589:21
  43: {closure#2}
             at /Users/timch/rust/compiler/rustc_driver_impl/src/lib.rs:325:29
  44: {closure#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1026:80
  45: call_once<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/core/src/panic/unwind_safe.rs:275:9
  46: do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>, core::option::Option<rustc_interface::queries::Linker>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:581:40
  47: catch_unwind<core::option::Option<rustc_interface::queries::Linker>, core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:544:19
  48: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>, core::option::Option<rustc_interface::queries::Linker>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panic.rs:359:14
  49: {closure#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:1026:23
  50: {closure#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context.rs:788:37
  51: {closure#0}<rustc_middle::ty::context::{impl#15}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context/tls.rs:56:9
  52: try_with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_middle::ty::context::{impl#15}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/thread/local.rs:462:12
  53: with<core::cell::Cell<*const ()>, rustc_middle::ty::context::tls::enter_context::{closure_env#0}<rustc_middle::ty::context::{impl#15}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/thread/local.rs:426:20
  54: enter_context<rustc_middle::ty::context::{impl#15}::enter::{closure_env#1}<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>, core::option::Option<rustc_interface::queries::Linker>>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context/tls.rs:53:9
  55: enter<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context.rs:788:9
  56: create_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>
             at /Users/timch/rust/compiler/rustc_middle/src/ty/context.rs:982:13
  57: create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>
             at /Users/timch/rust/compiler/rustc_interface/src/passes.rs:986:5
  58: {closure#0}
             at /Users/timch/rust/compiler/rustc_driver_impl/src/lib.rs:298:22
  59: {closure#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>
             at /Users/timch/rust/compiler/rustc_interface/src/interface.rs:495:80
  60: call_once<(), rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/core/src/panic/unwind_safe.rs:275:9
  61: do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:581:40
  62: catch_unwind<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panicking.rs:544:19
  63: catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()>
             at /rustc/ef0fb8a2563200e322fa4419f09f65a63742038c/library/std/src/panic.rs:359:14
  64: {closure#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>
             at /Users/timch/rust/compiler/rustc_interface/src/interface.rs:495:23
  65: {closure#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>
             at /Users/timch/rust/compiler/rustc_interface/src/util.rs:205:17
  66: {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>
             at /Users/timch/rust/compiler/rustc_interface/src/util.rs:161:24
  67: set<rustc_span::SessionGlobals, rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>
             at /Users/timch/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/scoped-tls-1.0.1/src/lib.rs:137:9
  68: create_session_globals_then<(), rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>>
             at /Users/timch/rust/compiler/rustc_span/src/lib.rs:154:21
  69: {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>
             at /Users/timch/rust/compiler/rustc_interface/src/util.rs:157:17
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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: please attach the file at `/Users/timch/foo/rustc-ice-2026-05-08T09_47_34-13835.txt` to your bug report

note: rustc 1.97.0-dev running on aarch64-apple-darwin

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked -C incremental=[REDACTED]

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

query stack during panic:
#0 [mir_borrowck] borrow-checking `main`
#1 [analysis] running analysis passes on crate `foo`
end of query stack
error: could not compile `foo` (bin "foo") due to 1 previous error

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    C-bugCategory: This is a bug.F-reborrow`#![feature(reborrow)]`; see #145612I-ICEIssue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️T-compilerRelevant to the compiler team, which will review and decide on the PR/issue.

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