internal compiler error: unexpected panic

[yonip23]

Hey all, I get this message when running clippy nightly on my project:

thread 'rustc' panicked at 'assertion failed: !value.has_escaping_bound_vars()', /rustc/2e35f954ada0f0c777844dc4fa66684efe90a035/compiler/rustc_middle/src/ty/sty.rs:1028:9
stack backtrace:
   0: rust_begin_unwind
             at /rustc/2e35f954ada0f0c777844dc4fa66684efe90a035/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/2e35f954ada0f0c777844dc4fa66684efe90a035/library/core/src/panicking.rs:142:14
   2: core::panicking::panic
             at /rustc/2e35f954ada0f0c777844dc4fa66684efe90a035/library/core/src/panicking.rs:48:5
   3: rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions
   4: <rustc_infer::infer::InferCtxtBuilder>::enter::<bool, rustc_ty_utils::common_traits::is_item_raw::{closure#0}>
   5: rustc_ty_utils::common_traits::is_sized_raw
   6: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Ty>, bool>
   7: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Ty>, bool>>
   8: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::is_sized_raw
   9: <rustc_middle::ty::Ty>::is_sized
  10: <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached
  11: rustc_middle::ty::layout::layout_of
  12: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::layout_of, rustc_query_impl::plumbing::QueryCtxt>
  13: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::layout_of
  14: <core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::FieldDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}::{closure#0}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>> as core::iter::traits::iterator::Iterator>::next
  15: <alloc::vec::Vec<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>> as alloc::vec::spec_from_iter::SpecFromIter<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>, core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::VariantDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>>>>::from_iter
  16: <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached
  17: rustc_middle::ty::layout::layout_of
  18: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::layout_of, rustc_query_impl::plumbing::QueryCtxt>
  19: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::layout_of
  20: <core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::FieldDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}::{closure#0}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>> as core::iter::traits::iterator::Iterator>::next
  21: <alloc::vec::Vec<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>> as alloc::vec::spec_from_iter::SpecFromIter<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>, core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::VariantDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>>>>::from_iter
  22: <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached
  23: rustc_middle::ty::layout::layout_of
  24: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::layout_of, rustc_query_impl::plumbing::QueryCtxt>
  25: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::layout_of
  26: <core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::FieldDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}::{closure#0}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>> as core::iter::traits::iterator::Iterator>::next
  27: <alloc::vec::Vec<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>> as alloc::vec::spec_from_iter::SpecFromIter<alloc::vec::Vec<rustc_target::abi::TyAndLayout<rustc_middle::ty::Ty>>, core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::VariantDef>, <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached::{closure#5}>, core::result::Result<core::convert::Infallible, rustc_middle::ty::layout::LayoutError>>>>::from_iter
  28: <rustc_middle::ty::layout::LayoutCx<rustc_middle::ty::context::TyCtxt>>::layout_of_uncached
  29: rustc_middle::ty::layout::layout_of
  30: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::layout_of, rustc_query_impl::plumbing::QueryCtxt>
  31: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::layout_of
  32: clippy_utils::ty::approx_ty_size
  33: clippy_lints::functions::result::check_impl_item
  34: <rustc_lint::early::EarlyLintPassObjects as rustc_lint::passes::EarlyLintPass>::check_attribute
  35: <rustc_lint::late::LateContextAndPass<rustc_lint::late::LateLintPassObjects> as rustc_hir::intravisit::Visitor>::visit_nested_impl_item
  36: rustc_hir::intravisit::walk_item::<rustc_lint::late::LateContextAndPass<rustc_lint::late::LateLintPassObjects>>
  37: <rustc_lint::late::LateContextAndPass<rustc_lint::late::LateLintPassObjects> as rustc_hir::intravisit::Visitor>::visit_nested_item
  38: rustc_hir::intravisit::walk_mod::<rustc_lint::late::LateContextAndPass<rustc_lint::late::LateLintPassObjects>>
  39: rustc_lint::late::late_lint_pass_crate::<rustc_lint::late::LateLintPassObjects>
  40: rustc_lint::late::late_lint_crate::<rustc_lint::BuiltinCombinedLateLintPass>
  41: <rustc_session::session::Session>::time::<(), rustc_lint::late::check_crate<rustc_lint::BuiltinCombinedLateLintPass, rustc_interface::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#0}::{closure#0}>
  42: <rustc_session::session::Session>::time::<(), rustc_interface::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}>
  43: <core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::passes::analysis::{closure#5}::{closure#1}> as core::ops::function::FnOnce<()>>::call_once
  44: rustc_interface::passes::analysis
  45: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, (), core::result::Result<(), rustc_errors::ErrorGuaranteed>>
  46: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<(), core::result::Result<(), rustc_errors::ErrorGuaranteed>>>
  47: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::analysis, rustc_query_impl::plumbing::QueryCtxt>
  48: <rustc_interface::passes::QueryContext>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}::{closure#3}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
  49: <rustc_interface::interface::Compiler>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_errors::ErrorGuaranteed>>
  50: rustc_span::with_source_map::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_interface::interface::create_compiler_and_run<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#1}>
  51: rustc_interface::interface::create_compiler_and_run::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>
  52: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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-clippy/issues/new

note: Clippy version: clippy 0.1.65 (2e35f95 2022-09-01)

query stack during panic:
#0 [is_sized_raw] computing whether `dyn core::error::Error` is `Sized`
#1 [layout_of] computing layout of `*const dyn core::error::Error`
#2 [layout_of] computing layout of `core::ptr::non_null::NonNull<dyn core::error::Error>`
#3 [layout_of] computing layout of `core::ptr::unique::Unique<dyn core::error::Error>`
#4 [layout_of] computing layout of `alloc::boxed::Box<dyn core::error::Error>`
#5 [analysis] running analysis passes on this crate
end of query stack

Info

1. clippy version (shown in the log): 0.1.65 (2e35f95 2022-09-01)
2. rustc version: rustc 1.65.0-nightly (2e35f954a 2022-09-01)
3. cargo version: cargo 1.65.0-nightly (4ed54cecc 2022-08-27)
4. The command I'm using to run clippy:

   cargo +nightly clippy -p <my_crate> --all-features -- --no-deps -D clippy::pedantic -D clippy::print_stdout -A clippy::missing_panics_doc -A clippy::must_use_candidate -A clippy::missing_errors_doc -A clippy::module_name_repetitions -A clippy::implicit_hasher -A unknown-lints

5. About my crate:
   1. It has 0 external dependencies, and is really small (one lib.rs with ~70 lines, and tests.rs with 12 lines)
   2. It has no "funny" code, no unsafe or anything
   3. It is part of a larger project with workspace configuration, and ~80 other crates (Idk if it helps, just trying to provide as much relevant context as I can)

6. os: Ubuntu 20.04

   Please lmk if there's anything else you need from me, and thank you for this amazing project! 🙂

[Jarcho]

I can't manage to make a repro. Can you share the code? It's failing on a Result type for some function.

[yonip23]

I can't manage to make a repro. Can you share the code? It's failing on a Result type for some function.

The Result hint allowed me to trim down chunks of my code and being able to reproduce with this minimal example:

use std::{
    error::Error,
    sync::{Mutex, MutexGuard},
};

#[cfg(test)]
mod tests;

pub type Result<'a, T> = std::result::Result<T, Box<dyn 'a + Error>>;

#[derive(Default)]
pub struct Foo<T: Send> {
    data: Mutex<T>,
}

pub struct WriteLock<'a, T: Send + 'a>(MutexGuard<'a, T>);

impl<'a, T: Send + 'a> WriteLock<'a, T> {
    pub fn get(&self) -> &T {
        &self.0
    }
}

impl<T: Sync + Send> Foo<T> {
    pub fn foo(&self) -> Result<WriteLock<T>> {
        Ok(WriteLock(self.data.try_lock()?))
    }
}

[Jarcho]

Looks like the latest nightly is working (2022-08-31)

[yonip23]

My clippy version is 09-01 🤔 As shown in my info section above ^

[Jarcho]

I guess the playground hadn't updated by the time I checked.

[yonip23]

Thank you so much for the quick response and fix!👏

[Jarcho]

The change will be in nightly about a week from now.

[poliorcetics]

Thanks for the very fast fix, we hit that too in our CI !