ice: rustdoc: `assertion failed: !infcx.is_in_snapshot() || self.usable_in_snapshot`

[matthiaskrgr]

Code

#![feature(generic_const_exprs)]
#![allow(incomplete_features)]

pub trait Enumerable {
    const N: usize;
}

#[derive(Clone)]
pub struct SymmetricGroup<S>
where
    S: Enumerable,
    [(); S::N]: Sized,
{
    _phantom: std::marker::PhantomData<S>,
}

fn main() {}

Meta

rustc --version --verbose:

rustdoc 1.68.0-nightly (3020239de 2023-01-09)
binary: rustdoc
commit-hash: unknown
commit-date: unknown
host: x86_64-unknown-linux-gnu
release: 1.68.0-nightly
LLVM version: 15.0.6

Error output

<output>

Backtrace

thread 'rustc' panicked at 'assertion failed: !infcx.is_in_snapshot() || self.usable_in_snapshot', compiler/rustc_trait_selection/src/traits/fulfill.rs:140:9
stack backtrace:
   0:     0x7fa143f6531a - std::backtrace_rs::backtrace::libunwind::trace::hdca77ab3bec44471
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fa143f6531a - std::backtrace_rs::backtrace::trace_unsynchronized::hfe4f6d6ad029d217
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fa143f6531a - std::sys_common::backtrace::_print_fmt::h4c8d5d821895e43e
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7fa143f6531a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h5adb97f2e886759a
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fa143fc855e - core::fmt::write::h828c59fc78b17391
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/core/src/fmt/mod.rs:1208:17
   5:     0x7fa143f557f5 - std::io::Write::write_fmt::h0c8f0d571d31812a
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/io/mod.rs:1682:15
   6:     0x7fa143f650e5 - std::sys_common::backtrace::_print::had90567330241219
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7fa143f650e5 - std::sys_common::backtrace::print::hbbbec0560e502261
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7fa143f67eaf - std::panicking::default_hook::{{closure}}::h2bb3889378be62ea
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/panicking.rs:267:22
   9:     0x7fa143f67beb - std::panicking::default_hook::hd81bf40f79f1c509
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/panicking.rs:286:9
  10:     0x7fa1472a25a4 - rustc_driver[f75a378c450d3976]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7fa143f686ed - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hce3fec4e8f82d2fd
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/alloc/src/boxed.rs:2002:9
  12:     0x7fa143f686ed - std::panicking::rust_panic_with_hook::hed3ef434931562fa
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/panicking.rs:692:13
  13:     0x7fa143f68422 - std::panicking::begin_panic_handler::{{closure}}::h1d8dbcf5f5b1c94f
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/panicking.rs:577:13
  14:     0x7fa143f657cc - std::sys_common::backtrace::__rust_end_short_backtrace::hb1771d014f6a43ea
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys_common/backtrace.rs:137:18
  15:     0x7fa143f68172 - rust_begin_unwind
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/panicking.rs:575:5
  16:     0x7fa143fc4f23 - core::panicking::panic_fmt::hb8d8d3d1d1f13c08
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/core/src/panicking.rs:64:14
  17:     0x7fa143fc4fbd - core::panicking::panic::hdc74384184a8bd20
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/core/src/panicking.rs:114:5
  18:     0x7fa1457efe41 - <rustc_trait_selection[9743eb012b39fd0d]::traits::fulfill::FulfillmentContext as rustc_infer[60f75aa3feaaa8ad]::traits::engine::TraitEngine>::register_predicate_obligation
  19:     0x7fa145ff103a - <dyn rustc_infer[60f75aa3feaaa8ad]::traits::engine::TraitEngine as rustc_infer[60f75aa3feaaa8ad]::traits::engine::TraitEngineExt>::register_predicate_obligations::<alloc[14d1267f31994f20]::vec::Vec<rustc_infer[60f75aa3feaaa8ad]::traits::Obligation<rustc_middle[d3830b30b3b6bcb0]::ty::Predicate>>>
  20:     0x7fa147e5c6ae - <rustc_trait_selection[9743eb012b39fd0d]::traits::engine::ObligationCtxt>::register_infer_ok_obligations::<()>
  21:     0x7fa147e5cb39 - <rustc_trait_selection[9743eb012b39fd0d]::traits::engine::ObligationCtxt>::eq::<rustc_middle[d3830b30b3b6bcb0]::ty::consts::Const>
  22:     0x7fa147eac47c - rustc_trait_selection[9743eb012b39fd0d]::traits::const_evaluatable::satisfied_from_param_env
  23:     0x7fa14545e46d - rustc_trait_selection[9743eb012b39fd0d]::traits::const_evaluatable::is_const_evaluatable
  24:     0x7fa145d85487 - <rustc_trait_selection[9743eb012b39fd0d]::traits::select::SelectionContext>::evaluate_predicates_recursively::<alloc[14d1267f31994f20]::vec::into_iter::IntoIter<rustc_infer[60f75aa3feaaa8ad]::traits::Obligation<rustc_middle[d3830b30b3b6bcb0]::ty::Predicate>>>
  25:     0x7fa145d6aa91 - <rustc_trait_selection[9743eb012b39fd0d]::traits::select::SelectionContext>::evaluate_stack
  26:     0x7fa145ce89b4 - <rustc_trait_selection[9743eb012b39fd0d]::traits::select::SelectionContext>::evaluate_predicate_recursively
  27:     0x7fa145ce658a - <rustc_infer[60f75aa3feaaa8ad]::infer::InferCtxt>::probe::<core[77a23254458137f7]::result::Result<rustc_middle[d3830b30b3b6bcb0]::traits::select::EvaluationResult, rustc_middle[d3830b30b3b6bcb0]::traits::select::OverflowError>, <rustc_trait_selection[9743eb012b39fd0d]::traits::select::SelectionContext>::evaluation_probe<<rustc_trait_selection[9743eb012b39fd0d]::traits::select::SelectionContext>::evaluate_root_obligation::{closure#0}>::{closure#0}>
  28:     0x7fa145ce3e1d - rustc_traits[7dfddbd6db681657]::evaluate_obligation::evaluate_obligation
  29:     0x7fa145ce047a - rustc_query_system[9558173104ffa4a8]::query::plumbing::get_query::<rustc_query_impl[344ffabf7d0c303e]::queries::evaluate_obligation, rustc_query_impl[344ffabf7d0c303e]::plumbing::QueryCtxt, rustc_middle[d3830b30b3b6bcb0]::dep_graph::dep_node::DepKind>
  30:     0x7fa145c25111 - <rustc_infer[60f75aa3feaaa8ad]::infer::InferCtxt as rustc_trait_selection[9743eb012b39fd0d]::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation
  31:     0x563959227c8b - <rustdoc[67b20287af1b411]::clean::blanket_impl::BlanketImplFinder>::get_blanket_impls
  32:     0x563958ee958a - rustdoc[67b20287af1b411]::clean::utils::get_auto_trait_and_blanket_impls
  33:     0x56395910e902 - <rustdoc[67b20287af1b411]::passes::collect_trait_impls::SyntheticImplCollector as rustdoc[67b20287af1b411]::visit::DocVisitor>::visit_item
  34:     0x56395910ea4a - <rustdoc[67b20287af1b411]::passes::collect_trait_impls::SyntheticImplCollector as rustdoc[67b20287af1b411]::visit::DocVisitor>::visit_item
  35:     0x56395910fb71 - <rustdoc[67b20287af1b411]::passes::collect_trait_impls::SyntheticImplCollector as rustdoc[67b20287af1b411]::visit::DocVisitor>::visit_crate
  36:     0x56395913af9c - <rustc_session[47a5956f246e9bfc]::session::Session>::time::<alloc[14d1267f31994f20]::vec::Vec<rustdoc[67b20287af1b411]::clean::types::Item>, rustdoc[67b20287af1b411]::passes::collect_trait_impls::collect_trait_impls::{closure#0}>
  37:     0x56395910c66a - rustdoc[67b20287af1b411]::passes::collect_trait_impls::collect_trait_impls
  38:     0x56395913b55e - <rustc_session[47a5956f246e9bfc]::session::Session>::time::<rustdoc[67b20287af1b411]::clean::types::Crate, rustdoc[67b20287af1b411]::core::run_global_ctxt::{closure#7}>
  39:     0x5639591070d9 - rustdoc[67b20287af1b411]::core::run_global_ctxt
  40:     0x56395913b82c - <rustc_session[47a5956f246e9bfc]::session::Session>::time::<(rustdoc[67b20287af1b411]::clean::types::Crate, rustdoc[67b20287af1b411]::config::RenderOptions, rustdoc[67b20287af1b411]::formats::cache::Cache), rustdoc[67b20287af1b411]::main_args::{closure#1}::{closure#0}::{closure#1}::{closure#0}>
  41:     0x563959175edf - <rustc_interface[faf3c08608b72f36]::passes::QueryContext>::enter::<rustdoc[67b20287af1b411]::main_args::{closure#1}::{closure#0}::{closure#1}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>
  42:     0x563958eb121a - <rustc_interface[faf3c08608b72f36]::interface::Compiler>::enter::<rustdoc[67b20287af1b411]::main_args::{closure#1}::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>
  43:     0x56395908f71a - rustc_span[2a613a2f02b6af2c]::with_source_map::<core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>, rustc_interface[faf3c08608b72f36]::interface::run_compiler<core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>, rustdoc[67b20287af1b411]::main_args::{closure#1}>::{closure#0}::{closure#0}>
  44:     0x5639590348e5 - <scoped_tls[cde101c268443f1a]::ScopedKey<rustc_span[2a613a2f02b6af2c]::SessionGlobals>>::set::<rustc_interface[faf3c08608b72f36]::interface::run_compiler<core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>, rustdoc[67b20287af1b411]::main_args::{closure#1}>::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>
  45:     0x5639590f0770 - std[f433d76e435f6f2]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[faf3c08608b72f36]::util::run_in_thread_pool_with_globals<rustc_interface[faf3c08608b72f36]::interface::run_compiler<core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>, rustdoc[67b20287af1b411]::main_args::{closure#1}>::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>
  46:     0x5639591d76af - <<std[f433d76e435f6f2]::thread::Builder>::spawn_unchecked_<rustc_interface[faf3c08608b72f36]::util::run_in_thread_pool_with_globals<rustc_interface[faf3c08608b72f36]::interface::run_compiler<core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>, rustdoc[67b20287af1b411]::main_args::{closure#1}>::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[77a23254458137f7]::result::Result<(), rustc_errors[515aeced1161bc4]::ErrorGuaranteed>>::{closure#1} as core[77a23254458137f7]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  47:     0x7fa143f72b23 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h8f2b7af54766d232
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/alloc/src/boxed.rs:1988:9
  48:     0x7fa143f72b23 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hdc261654aadd28fc
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/alloc/src/boxed.rs:1988:9
  49:     0x7fa143f72b23 - std::sys::unix::thread::Thread::new::thread_start::h2ffe427b25515558
                               at /rustc/3020239de947ec52677e9b4e853a6a9fc073d1f9/library/std/src/sys/unix/thread.rs:108:17
  50:     0x7fa143d048fd - <unknown>
  51:     0x7fa143d86a60 - <unknown>
  52:                0x0 - <unknown>

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 1.68.0-nightly (3020239de 2023-01-09) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `SymmetricGroup<^1_0>: core::clone::Clone`
end of query stack

[GuillaumeGomez]

That seems to be something for the compiler team instead. I'll add the tag.