borrow checker ICE

[donkeyteethUX]

Code

This seems to be the problematic function. Obviously the code is not a reproducible example. If I have time I will try to add one. For some small context, channels is a tuple of crossbeam sender & receiver.

    fn listen(&mut self) {
        let run = |nframe: NFrame| -> Result<NFrame> {
            Self::check_kps(&nframe)?;
            self.nframe = nframe;
            self.nframe.generate_bow_set_diridx(&self.sg.bow_vocab);
            self.do_reloc()?;
            Ok(self.nframe.clone()) // todo: can avoid this clone
        };
        loop {
            let nframe = unwrap_or_continue!(self.channels.as_ref().unwrap().1.recv_timeout(Duration::new(1, 0)).ok());
            let result = run(nframe);
            self.channels.as_ref().unwrap().0.send(result.unwrap());
        }
    }

rustc --version --verbose:

rustc 1.51.0-nightly (04caa632d 2021-01-30)
binary: rustc
commit-hash: 04caa632dd10c2bf64b69524c7f9c4c30a436877
commit-date: 2021-01-30
host: x86_64-unknown-linux-gnu
release: 1.51.0-nightly
LLVM version: 11.0.1

Error output

error: internal compiler error: compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs:505:22: upvar `self` borrowed, but not mutably

thread 'rustc' panicked at 'Box<Any>', compiler/rustc_errors/src/lib.rs:958:9
stack backtrace:
   0: std::panicking::begin_panic
   1: rustc_errors::HandlerInner::bug
   2: rustc_errors::Handler::bug
   3: rustc_middle::ty::context::tls::with_opt
   4: rustc_middle::util::bug::opt_span_bug_fmt
   5: rustc_middle::util::bug::bug_fmt
   6: rustc_mir::borrow_check::diagnostics::mutability_errors::<impl rustc_mir::borrow_check::MirBorrowckCtxt>::show_mutating_upvar
   7: rustc_mir::borrow_check::diagnostics::mutability_errors::<impl rustc_mir::borrow_check::MirBorrowckCtxt>::report_mutability_error
   8: rustc_mir::borrow_check::MirBorrowckCtxt::access_place
   9: <rustc_mir::borrow_check::MirBorrowckCtxt as rustc_mir::dataflow::framework::visitor::ResultsVisitor>::visit_statement_before_primary_effect
  10: <rustc_mir::dataflow::framework::direction::Forward as rustc_mir::dataflow::framework::direction::Direction>::visit_results_in_block
  11: rustc_mir::dataflow::framework::visitor::visit_results
  12: rustc_mir::borrow_check::do_mir_borrowck
  13: rustc_infer::infer::InferCtxtBuilder::enter
  14: rustc_mir::borrow_check::mir_borrowck
  15: core::ops::function::FnOnce::call_once
  16: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::mir_borrowck>::compute
  17: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  18: rustc_data_structures::stack::ensure_sufficient_stack
  19: rustc_query_system::query::plumbing::force_query_with_job
  20: rustc_query_system::query::plumbing::get_query_impl
  21: rustc_query_system::query::plumbing::ensure_query_impl
  22: rustc_interface::passes::analysis
  23: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
  24: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  25: rustc_middle::ty::query::plumbing::<impl rustc_query_system::query::QueryContext for rustc_middle::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}::{{closure}}
  26: rustc_query_system::query::plumbing::force_query_with_job
  27: rustc_query_system::query::plumbing::get_query_impl
  28: rustc_interface::passes::QueryContext::enter
  29: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  30: rustc_span::with_source_map
  31: rustc_interface::interface::create_compiler_and_run
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 1.51.0-nightly (04caa632d 2021-01-30) running on x86_64-unknown-linux-gnu

note: compiler flags: -C opt-level=3 -C embed-bitcode=no -C debuginfo=2 --crate-type lib

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

query stack during panic:
#0 [mir_borrowck] borrow-checking `systems::relocalize::Relocalizer::listen`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error; 9 warnings emitted

error: could not compile `atlas`

To learn more, run the command again with --verbose.

[osa1]

@rustbot label: +A-borrow-checker +E-needs-mcve

[donkeyteethUX]

Compiler works fine here on the latest nightly. I guess the issue has been fixed, so I won't bother working on a minimal example unless somebody really wants it.

[osa1]

This is probably a duplicate of #81700 and can be closed as the issue is already fixed.