Bug: ICE upvar self borrowed but not mutably./

[brightly-salty]

I recieved this unexpected output when running cargo clippy on a branch of scryer-prolog:

➜  scryer-prolog git:(clippy-warnings) ✗ cargo clippy
    Checking scryer-prolog v0.8.127 (/Users/cadenhaustein/Documents/GitHub/scryer-prolog)
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
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust-clippy/issues/new

note: Clippy version: clippy 0.1.51 (04caa632 2021-01-30)

query stack during panic:
#0 [mir_borrowck] borrow-checking `machine::loader::<impl machine::Machine>::compile_user_assert`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

error: could not compile `scryer-prolog`

To learn more, run the command again with --verbose.
➜  scryer-prolog git:(clippy-warnings) ✗

[giraffate]

Do you mean https://github.com/mthom/scryer-prolog? I can't reproduce the ICE on it. Can you provide a minmal reproduction? FYI I used versions below.

$ rustc -V
rustc 1.51.0-nightly (04caa632d 2021-01-30)
$ cargo clippy -V
clippy 0.1.51 (04caa632 2021-01-30)

[brightly-salty]

Yes, that is the repository I'm talking about. I'm not sure what a minimal reproduction would look like. The ICE occurred (and continues to occur) on my branch of scryer-prolog located here https://github.com/brightly-salty/scryer-prolog/tree/clippy-warnings.

[giraffate]

Thanks for more info! I reproduced the ICE on your branch, not master branch.

backtrace

$ RUST_BACKTRACE=full cargo clippy
    Checking scryer-prolog v0.8.127 (/Users/tnakata/workspace/scryer-prolog)
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:        0x10b06514c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hd841328aa7dc06cc
   1:        0x10b0c964d - core::fmt::write::hefe95a44532fe6ed
   2:        0x10b057566 - std::io::Write::write_fmt::haeb49d4f9ecd789d
   3:        0x10b069019 - std::panicking::default_hook::{{closure}}::h465a961bccd4d390
   4:        0x10b068ba9 - std::panicking::default_hook::h7e189743c9acab0a
   5:        0x10a8df196 - clippy_driver::ICE_HOOK::{{closure}}::{{closure}}::hffcc4974016a412f
   6:        0x10b0697fe - std::panicking::rust_panic_with_hook::he74e9eac8174d6dd
   7:        0x111db5e71 - std::panicking::begin_panic::{{closure}}::h1a854b08a8e555cf
   8:        0x111db54e9 - std::sys_common::backtrace::__rust_end_short_backtrace::hf1abdc991e575939
   9:        0x1121ed771 - std::panicking::begin_panic::hecd46e606ef09612
  10:        0x111dc6eb3 - rustc_errors::HandlerInner::bug::h066d497cb78aa433
  11:        0x111dc54f7 - rustc_errors::Handler::bug::hbbe34ee08190d52e
  12:        0x111af50d4 - rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}::hcb6f3762eadf3759
  13:        0x111ae4e80 - rustc_middle::ty::context::tls::with_opt::hbfca6f1350360576
  14:        0x111af4ffb - rustc_middle::util::bug::opt_span_bug_fmt::h968305499b0e0c93
  15:        0x1121e9e2f - rustc_middle::util::bug::bug_fmt::h5677cca955f8a8e7
  16:        0x1109dd04b - rustc_mir::borrow_check::diagnostics::mutability_errors::<impl rustc_mir::borrow_check::MirBorrowckCtxt>::show_mutating_upvar::hb322b9c4f9709e4e
  17:        0x1109d9e16 - rustc_mir::borrow_check::diagnostics::mutability_errors::<impl rustc_mir::borrow_check::MirBorrowckCtxt>::report_mutability_error::hc7b041ae3de99f2a
  18:        0x1109e94bc - rustc_mir::borrow_check::MirBorrowckCtxt::access_place::h4314fdc54afb3a93
  19:        0x1109e797b - <rustc_mir::borrow_check::MirBorrowckCtxt as rustc_mir::dataflow::framework::visitor::ResultsVisitor>::visit_statement_before_primary_effect::hf55d038c32a8c29a
  20:        0x11080205b - <rustc_mir::dataflow::framework::direction::Forward as rustc_mir::dataflow::framework::direction::Direction>::visit_results_in_block::h5df776b90c85a1b9
  21:        0x1105a64f9 - rustc_mir::dataflow::framework::visitor::visit_results::hb1708c11114be106
  22:        0x1109e4c68 - rustc_mir::borrow_check::do_mir_borrowck::h2dc5f59581148b4b
  23:        0x1104fe95f - rustc_infer::infer::InferCtxtBuilder::enter::h3266db50977833ec
  24:        0x1109e1421 - rustc_mir::borrow_check::mir_borrowck::h8cdf24d72772d6b9
  25:        0x11099b1d7 - core::ops::function::FnOnce::call_once::h02ef1621e2fc32e1
  26:        0x10d9c051d - 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::h06c7088aeb79dd31
  27:        0x10d9650e1 - rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::h88a1e91358267ce4
  28:        0x10d90eff1 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl::ha94e290b224f6b26
  29:        0x10d9c1e9f - rustc_data_structures::stack::ensure_sufficient_stack::h5f4104d60ff4185a
  30:        0x10d9f758d - rustc_query_system::query::plumbing::force_query_with_job::h93e948c3b04cbd35
  31:        0x10d9ed78f - rustc_query_system::query::plumbing::get_query_impl::h60c29221e5f676a8
  32:        0x10d9f4561 - rustc_query_system::query::plumbing::ensure_query_impl::h792f2db8fbdc85f0
  33:        0x10d99b5a2 - rustc_interface::passes::analysis::h8ea409ff1683f2f5
  34:        0x10d8021f2 - rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute::hb634e64b60b99d7c
  35:        0x10d77c791 - rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::h3bb49e028fec11ae
  36:        0x10d7f654e - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl::hd63d3990f4ddd3b5
  37:        0x10d802310 - rustc_middle::ty::query::plumbing::<impl rustc_query_system::query::QueryContext for rustc_middle::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}::{{closure}}::h17505854bc4f5a47
  38:        0x10d7a6fe9 - rustc_query_system::query::plumbing::force_query_with_job::h16308705307332d5
  39:        0x10d7a30c5 - rustc_query_system::query::plumbing::get_query_impl::h0aff3630147dc518
  40:        0x10d808eaa - rustc_interface::passes::QueryContext::enter::hec3391619f1c0034
  41:        0x10d77ec93 - rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter::h5ae1a861e2ef017b
  42:        0x10d7fdede - rustc_span::with_source_map::hb15b187d8726f95a
  43:        0x10d77fed4 - rustc_interface::interface::create_compiler_and_run::h676e33808641f5cb
  44:        0x10d80a713 - std::sys_common::backtrace::__rust_begin_short_backtrace::h17f5da3f25073b11
  45:        0x10d7a99a9 - core::ops::function::FnOnce::call_once{{vtable.shim}}::h099c825c1a0d0ef5
  46:        0x10b076a0d - std::sys::unix::thread::Thread::new::thread_start::h23116ad77b076564
  47:     0x7fff6a22b109 - __pthread_start

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust-clippy/issues/new

note: Clippy version: clippy 0.1.51 (04caa632 2021-01-30)

query stack during panic:
#0 [mir_borrowck] borrow-checking `machine::loader::<impl machine::Machine>::compile_user_assert`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

error: could not compile `scryer-prolog`

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

[brightly-salty]

@giraffate Looks like it might be similar to/a duplicate of rust-lang/rust#81700. I'll keep this issue up until that commit gets into rust-nightly, and then test again. If it works, I'll close the issue. Does that sound good?

[giraffate]

Looks good, thanks!

[giraffate]

I tried again on versions below, ICE doesn't happen. It seems to be fixed, so I'm closing this.

$ rustc -V
rustc 1.52.0-nightly (9778068cb 2021-02-07)
$ cargo clippy -V
clippy 0.1.52 (9778068c 2021-02-07)