Internal Compiler Error: found unstable fingerprints for predicates_of(Send/From/Eq/etc.)

[stijnfrishert]

I've run into an internal compiler error. I'm not sure if I can create a simplified code sample for why this happened, and part of the codebase is proprietary, but I hope this helps anyway.

One of the traces talks about "checking that audio_driver::<impl at jpt/src/audio_drive.rs> is well-formed", so I've included that file.

use cpal::{
    traits::{DeviceTrait, HostTrait, StreamTrait},
    BufferSize, Device, OutputCallbackInfo, SampleRate, Stream, StreamConfig,
};
use std::ops::Range;

pub struct AudioDriver {
    _device: Device,
    _stream: Stream,
}

impl AudioDriver {
    pub fn new<Handler>(channel_count: u16, sample_rate: u32, mut handler: Handler) -> Option<Self>
    where
        Handler: FnMut(&[*const f32], &[*mut f32], Range<usize>) + Send + 'static,
    {
        let host = cpal::default_host();

        let device = host
            .default_output_device()
            .expect("failed to find a default output device");

        println!("Using default output device: '{}'", device.name().ok()?);

        let mut config: StreamConfig = device.default_output_config().ok()?.into();
        let block_size = 512;

        config.sample_rate = SampleRate(sample_rate);
        config.channels = channel_count;
        config.buffer_size = BufferSize::Fixed(block_size);
        println!("Using default output stream config: {:?}", config);

        let buffer = DeinterleavedBuffer::new(channel_count as usize, block_size as usize);
        let stream = device
            .build_output_stream(
                &config,
                move |data: &mut [f32], _: &OutputCallbackInfo| {
                    handler(&[], &buffer.ptrs, 0..data.len() / channel_count as usize);
                    buffer.interleave(data);
                },
                move |err| {
                    eprintln!("an error occurred on stream: {}", err);
                },
            )
            .ok()?;

        stream.play().ok()?;

        Some(Self {
            _device: device,
            _stream: stream,
        })
    }
}

struct DeinterleavedBuffer {
    data: Vec<f32>,
    pub ptrs: Vec<*mut f32>,
    channels: usize,
    block_size: usize,
}

impl DeinterleavedBuffer {
    pub fn new(channels: usize, block_size: usize) -> Self {
        let mut data = Vec::new();
        data.resize(channels * block_size, 0.0);

        let mut ptrs = Vec::with_capacity(channels);
        ptrs.resize(channels, std::ptr::null_mut());

        let ptr = data.as_mut_ptr();
        for c in 0..channels {
            let address = unsafe { ptr.offset((c * block_size) as isize) };
            ptrs[c] = address;
        }

        Self {
            data,
            ptrs,
            channels,
            block_size,
        }
    }

    pub fn interleave(&self, out: &mut [f32]) {
        assert!(out.len() <= self.data.len());

        let block_size = out.len() / self.channels;

        for f in 0..block_size {
            for c in 0..self.channels {
                out[f * self.channels + c] = self.data[c * self.block_size + f];
            }
        }
    }
}

unsafe impl Send for DeinterleavedBuffer {}

Meta

rustc --version --verbose:

rustc 1.53.0-nightly (673d0db5e 2021-03-23)
binary: rustc
commit-hash: 673d0db5e393e9c64897005b470bfeb6d5aec61b
commit-date: 2021-03-23
host: x86_64-apple-darwin
release: 1.53.0-nightly
LLVM version: 12.0.0

Error output

thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Send): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Send>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:38:1: 38:27 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
note: run with `RUST_BACKTRACE=1` environment variable to display a 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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Send`
#1 [check_item_well_formed] checking that `audio_driver::<impl at jpt/src/audio_driver.rs:98:1: 98:44>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::convert::From): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:20: 365:25 (#0)), (Binder(TraitPredicate(<T as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:16: 365:17 (#0)), (Binder(TraitPredicate(<Self as std::convert::From<T>>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:1: 365:25 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::convert::From`
#1 [check_item_well_formed] checking that `chord_exercise::<impl at jpt/src/chord_exercise.rs:108:1: 115:2>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::StructuralEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::StructuralEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:205:1: 205:23 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::StructuralEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:41: 4:43>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::cmp::Eq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::cmp::PartialEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:268:15: 268:30 (#0)), (Binder(TraitPredicate(<Self as std::cmp::Eq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:268:1: 268:30 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::cmp::Eq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:41: 4:43>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::StructuralPartialEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::StructuralPartialEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:152:1: 152:30 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::StructuralPartialEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:30: 4:39>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::cmp::PartialEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::cmp::PartialEq<Rhs>>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:202:1: 202:40 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::cmp::PartialEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:30: 4:39>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::clone::Clone): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/clone.rs:108:18: 108:23 (#0)), (Binder(TraitPredicate(<Self as std::clone::Clone>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/clone.rs:108:1: 108:23 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::clone::Clone`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:23: 4:28>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Copy): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::clone::Clone>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:385:17: 385:22 (#0)), (Binder(TraitPredicate(<Self as std::marker::Copy>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:385:1: 385:22 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Copy`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:17: 4:21>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::fmt::Debug): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::fmt::Debug>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/fmt/mod.rs:550:1: 550:16 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::fmt::Debug`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:10: 4:15>` is well-formed
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Sized): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:92:1: 92:16 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5

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 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Sized`
#1 [check_impl_item_well_formed] checking that `audio_driver::<impl at jpt/src/audio_driver.rs:12:1: 54:2>::new` is well-formed
end of query stack

Backtrace

thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Send): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Send>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:38:1: 38:27 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Send`
#1 [check_item_well_formed] checking that `audio_driver::<impl at jpt/src/audio_driver.rs:98:1: 98:44>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::convert::From): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:20: 365:25 (#0)), (Binder(TraitPredicate(<T as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:16: 365:17 (#0)), (Binder(TraitPredicate(<Self as std::convert::From<T>>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:1: 365:25 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::convert::From`
#1 [check_item_well_formed] checking that `chord_exercise::<impl at jpt/src/chord_exercise.rs:108:1: 115:2>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::StructuralEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::StructuralEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:205:1: 205:23 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::StructuralEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:41: 4:43>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::cmp::Eq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::cmp::PartialEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:268:15: 268:30 (#0)), (Binder(TraitPredicate(<Self as std::cmp::Eq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:268:1: 268:30 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::cmp::Eq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:41: 4:43>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::StructuralPartialEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::StructuralPartialEq>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:152:1: 152:30 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::StructuralPartialEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:30: 4:39>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::cmp::PartialEq): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::cmp::PartialEq<Rhs>>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/cmp.rs:202:1: 202:40 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::cmp::PartialEq`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:30: 4:39>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::clone::Clone): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/clone.rs:108:18: 108:23 (#0)), (Binder(TraitPredicate(<Self as std::clone::Clone>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/clone.rs:108:1: 108:23 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::clone::Clone`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:23: 4:28>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Copy): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::clone::Clone>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:385:17: 385:22 (#0)), (Binder(TraitPredicate(<Self as std::marker::Copy>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:385:1: 385:22 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Copy`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:17: 4:21>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::fmt::Debug): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::fmt::Debug>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/fmt/mod.rs:550:1: 550:16 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::trait_obligations
  10: rustc_infer::infer::InferCtxtBuilder::enter
  11: rustc_typeck::check::wfcheck::check_item_well_formed
  12: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  13: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: rustc_query_system::query::plumbing::force_query_with_job
  16: rustc_query_system::query::plumbing::get_query_impl
  17: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_item_well_formed
  18: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_item
  19: rustc_data_structures::sync::par_for_each_in
  20: rustc_hir::hir::Crate::par_visit_all_item_likes
  21: rustc_session::session::Session::track_errors
  22: rustc_typeck::check_crate
  23: rustc_interface::passes::analysis
  24: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  25: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  26: rustc_data_structures::stack::ensure_sufficient_stack
  27: rustc_query_system::query::plumbing::force_query_with_job
  28: rustc_query_system::query::plumbing::get_query_impl
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  30: rustc_interface::passes::QueryContext::enter
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: rustc_interface::interface::create_compiler_and_run
  34: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::fmt::Debug`
#1 [check_item_well_formed] checking that `chord::<impl at jpt/src/chord.rs:4:10: 4:15>` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[40e9]::marker::Sized): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /Users/stijn/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/src/rust/library/core/src/marker.rs:92:1: 92:16 (#0))] }', /rustc/673d0db5e393e9c64897005b470bfeb6d5aec61b/compiler/rustc_query_system/src/query/plumbing.rs:593:5
stack backtrace:
   0: _rust_begin_unwind
   1: std::panicking::begin_panic_fmt
   2: rustc_query_system::query::plumbing::incremental_verify_ich
   3: rustc_query_system::query::plumbing::load_from_disk_and_cache_in_memory
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: rustc_query_system::query::plumbing::get_query_impl
   6: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::predicates_of
   7: rustc_trait_selection::traits::wf::WfPredicates::nominal_obligations
   8: rustc_trait_selection::traits::wf::WfPredicates::compute_trait_ref
   9: rustc_trait_selection::traits::wf::predicate_obligations
  10: rustc_typeck::check::wfcheck::check_where_clauses
  11: rustc_typeck::check::wfcheck::check_fn_or_method
  12: rustc_infer::infer::InferCtxtBuilder::enter
  13: rustc_typeck::check::wfcheck::check_associated_item
  14: rustc_typeck::check::check::check_impl_item_well_formed
  15: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  16: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  17: rustc_data_structures::stack::ensure_sufficient_stack
  18: rustc_query_system::query::plumbing::force_query_with_job
  19: rustc_query_system::query::plumbing::get_query_impl
  20: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_impl_item_well_formed
  21: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc_hir::intravisit::Visitor>::visit_impl_item
  22: rustc_data_structures::sync::par_for_each_in
  23: rustc_hir::hir::Crate::par_visit_all_item_likes
  24: rustc_session::session::Session::track_errors
  25: rustc_typeck::check_crate
  26: rustc_interface::passes::analysis
  27: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  28: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  29: rustc_data_structures::stack::ensure_sufficient_stack
  30: rustc_query_system::query::plumbing::force_query_with_job
  31: rustc_query_system::query::plumbing::get_query_impl
  32: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis
  33: rustc_interface::passes::QueryContext::enter
  34: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  35: rustc_span::with_source_map
  36: rustc_interface::interface::create_compiler_and_run
  37: scoped_tls::ScopedKey<T>::set
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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.53.0-nightly (673d0db5e 2021-03-23) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [predicates_of] computing predicates of `std::marker::Sized`
#1 [check_impl_item_well_formed] checking that `audio_driver::<impl at jpt/src/audio_driver.rs:12:1: 54:2>::new` is well-formed
#2 [analysis] running analysis passes on this crate
end of query stack

[Aaron1011]

Does this still happen on the latest nightly?

[Aaron1011]

This error is extremely odd - it doesn't appear to involve your code at all.
@stijnfrishert: Are you able to consistently reproduce this error? Have you manually modified any of files in /Users/stijn/.rustup/toolchains/?

[stijnfrishert]

I was able to replicate it by running cargo build a couple of times after each other. Happened every time.

I cleaned everything and then everything compiled fine. Can't make it happen anymore now, so I wouldn't know if it still happens on the latest nightly, sorry.

I haven't touched any files in .rustup (didn't even know that existed).

If there's anything I can do to help, don't hesitate to ask!

[Aaron1011]

I'm just now seeing the other error message in the log you posted. I'm tempted to say that this was due to some kind of corruption of the incremental cache - I have no idea how any of these errors could occur.

If this happens again, please let me know.

[stijnfrishert]

I will, thanks! I understand this is one of those "hard to replicate, so who knows what happened? 🤷 " issues.

[Aaron1011]

It looks like this is not actually due to corruption - it showed up in a completely different project (#83523), also with predicates_of for a trait in libstd.

[stijnfrishert]

Ah, that's great news! Looks like you've chased the problem down already.

I totally agree with Casperin in the other issue, I'm just happy to contribute to this great language and team :)

[Aaron1011]

Duplicate of #84341. This is fixed in the latest nightly