assertion failed: !value.has_escaping_bound_vars()

[vorot93]

Code

This commit reliably crashes rustc:
akula-bft/akula@b28cbce

I haven't managed to minify this as the following works just fine:

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

pub trait Encode {
    type Encoded;

    fn encode(self) -> Self::Encoded;
}

impl Encode for u64 {
    type Encoded = [u8; 8];

    fn encode(self) -> Self::Encoded {
        self.to_be_bytes()
    }
}

impl<A, B, const A_LEN: usize, const B_LEN: usize> Encode for (A, B)
where
    A: Encode<Encoded = [u8; A_LEN]>,
    B: Encode<Encoded = [u8; B_LEN]>,
    [u8; A_LEN + B_LEN]: AsRef<[u8]>,
{
    type Encoded = [u8; A_LEN + B_LEN];

    fn encode(self) -> Self::Encoded {
        let mut v = [0; A_LEN + B_LEN];
        v[..A_LEN].copy_from_slice(&self.0.encode());
        v[A_LEN..].copy_from_slice(&self.1.encode());
        v
    }
}

fn main() {
    assert_eq!(Encode::encode((0, 0)), [0; 16]);
}

Meta

rustc --version --verbose:

rustc 1.57.0-nightly (ac2d9fc50 2021-09-21)
binary: rustc
commit-hash: ac2d9fc509e36d1b32513744adf58c34bcc4f43c
commit-date: 2021-09-21
host: x86_64-unknown-linux-gnu
release: 1.57.0-nightly
LLVM version: 13.0.0

Error output and backtrace

thread 'rustc' panicked at 'assertion failed: !value.has_escaping_bound_vars()', /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/compiler/rustc_middle/src/ty/sty.rs:971:9
stack backtrace:
   0:     0x7fb310ef651c - std::backtrace_rs::backtrace::libunwind::trace::h2ab374bc2a3b7023
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/../../backtrace/src/backtrace/libunwind.rs:90:5
   1:     0x7fb310ef651c - std::backtrace_rs::backtrace::trace_unsynchronized::h128cb5178b04dc46
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb310ef651c - std::sys_common::backtrace::_print_fmt::h5344f9eefca2041f
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys_common/backtrace.rs:67:5
   3:     0x7fb310ef651c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h213003bc5c7acf04
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys_common/backtrace.rs:46:22
   4:     0x7fb310f547dc - core::fmt::write::h78bf85fc3e93663f
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/core/src/fmt/mod.rs:1126:17
   5:     0x7fb310ee7405 - std::io::Write::write_fmt::he619515c888f21a5
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/io/mod.rs:1667:15
   6:     0x7fb310ef9a80 - std::sys_common::backtrace::_print::hf706674f77848203
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys_common/backtrace.rs:49:5
   7:     0x7fb310ef9a80 - std::sys_common::backtrace::print::hf0b6c7a88804ec56
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys_common/backtrace.rs:36:9
   8:     0x7fb310ef9a80 - std::panicking::default_hook::{{closure}}::h2dde766cd83a333a
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/panicking.rs:210:50
   9:     0x7fb310ef9637 - std::panicking::default_hook::h501e3b2e134eb149
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/panicking.rs:227:9
  10:     0x7fb3116dbe11 - rustc_driver::DEFAULT_HOOK::{{closure}}::{{closure}}::h8ff5de92123cb8fd
  11:     0x7fb2fee289f3 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hcaa339890b8e6472
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/alloc/src/boxed.rs:1650:9
  12:     0x7fb2fee2bd8d - proc_macro::bridge::client::<impl proc_macro::bridge::Bridge>::enter::{{closure}}::{{closure}}::hbacbce1e3e000948
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/proc_macro/src/bridge/client.rs:320:21
  13:     0x7fb310efa299 - std::panicking::rust_panic_with_hook::hc09e869c4cf00885
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/panicking.rs:628:17
  14:     0x7fb310ef9d22 - std::panicking::begin_panic_handler::{{closure}}::hc2c6d70142458fc8
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/panicking.rs:519:13
  15:     0x7fb310ef69c4 - std::sys_common::backtrace::__rust_end_short_backtrace::had58f7c459a1cd6e
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys_common/backtrace.rs:141:18
  16:     0x7fb310ef9cb9 - rust_begin_unwind
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/panicking.rs:517:5
  17:     0x7fb310ebf861 - core::panicking::panic_fmt::hf443e5eeb6cc9eab
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/core/src/panicking.rs:103:14
  18:     0x7fb310ebf7ad - core::panicking::panic::h50b51d19800453c0
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/core/src/panicking.rs:50:5
  19:     0x7fb3130feeba - rustc_trait_selection::traits::wf::WfPredicates::compute::h451c719e098064fd
  20:     0x7fb3130fc9a6 - rustc_trait_selection::traits::wf::obligations::h5b5581296da2e62f
  21:     0x7fb3130ac919 - rustc_trait_selection::traits::fulfill::FulfillProcessor::progress_changed_obligations::ha0aa535d762060d9
  22:     0x7fb3130c444b - rustc_data_structures::obligation_forest::ObligationForest<O>::process_obligations::h9b19112ccc099349
  23:     0x7fb3130abe4c - rustc_trait_selection::traits::fulfill::FulfillmentContext::select::h5feaa97543394f08
  24:     0x7fb3130ac5b2 - <rustc_trait_selection::traits::fulfill::FulfillmentContext as rustc_infer::traits::engine::TraitEngine>::select_with_constness_where_possible::h3885ead61348d1bd
  25:     0x7fb3130ac320 - <rustc_trait_selection::traits::fulfill::FulfillmentContext as rustc_infer::traits::engine::TraitEngine>::select_all_with_constness_or_error::h09a89888f1392f5a
  26:     0x7fb3129f2ec1 - rustc_typeck::check::fn_ctxt::_impl::<impl rustc_typeck::check::fn_ctxt::FnCtxt>::select_all_obligations_or_error::hcea71775409d9908
  27:     0x7fb312a66676 - rustc_infer::infer::InferCtxtBuilder::enter::hb9b185b080f31781
  28:     0x7fb312a2ae03 - rustc_typeck::check::typeck::hd320344c890821b5
  29:     0x7fb313899ef1 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h387037e7d39cafef
  30:     0x7fb313841f43 - rustc_data_structures::stack::ensure_sufficient_stack::h9e9042d5d4151ec7
  31:     0x7fb312de3b65 - rustc_query_system::query::plumbing::try_execute_query::h5bbb54711c9a400d
  32:     0x7fb312e5ce49 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck::h32b5ef98ec541fe2
  33:     0x7fb31319016c - rustc_middle::ty::context::TyCtxt::typeck_opt_const_arg::hd8495a4ee78e8a50
  34:     0x7fb312c2dca5 - rustc_mir_build::build::mir_built::hf1d3206186982bda
  35:     0x7fb31388d1cb - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h04fbae3ecd8247ff
  36:     0x7fb313848bd5 - rustc_data_structures::stack::ensure_sufficient_stack::hfd752616032c7244
  37:     0x7fb312df508c - rustc_query_system::query::plumbing::try_execute_query::hbfac2572e6fdd956
  38:     0x7fb312e5b131 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::mir_built::hb0174b933d0dcf4a
  39:     0x7fb3129ac573 - rustc_mir_transform::check_unsafety::unsafety_check_result::h2855d05d664d09ed
  40:     0x7fb3129a89ca - core::ops::function::FnOnce::call_once::h3ce14a99508d3a8a
  41:     0x7fb3138c3c01 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::hec0938501a20b61f
  42:     0x7fb31383f013 - rustc_data_structures::stack::ensure_sufficient_stack::h744d6d334b641c8b
  43:     0x7fb312df3395 - rustc_query_system::query::plumbing::try_execute_query::hab979f6c36b68b4b
  44:     0x7fb312e5ca4f - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::unsafety_check_result::h267ac8e757c55ecb
  45:     0x7fb3129a2854 - rustc_mir_transform::mir_const::hc5a3b65ee147fc8e
  46:     0x7fb31388d1cb - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h04fbae3ecd8247ff
  47:     0x7fb313848bd5 - rustc_data_structures::stack::ensure_sufficient_stack::hfd752616032c7244
  48:     0x7fb312df508c - rustc_query_system::query::plumbing::try_execute_query::hbfac2572e6fdd956
  49:     0x7fb312e5b281 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::mir_const::h74f2e1d3e042aff3
  50:     0x7fb3129a3bbe - rustc_mir_transform::mir_promoted::ha2e008bd04ccb8a5
  51:     0x7fb31388eca1 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h0a4b22006de86808
  52:     0x7fb313847047 - rustc_data_structures::stack::ensure_sufficient_stack::he760321fc26d1c7c
  53:     0x7fb312e12307 - rustc_query_system::query::plumbing::get_query::h5683cd12099c7a66
  54:     0x7fb312cfb9c6 - rustc_borrowck::mir_borrowck::h43f04ab543d2f43f
  55:     0x7fb312cf6d61 - core::ops::function::FnOnce::call_once::h8103cea540657a78
  56:     0x7fb313894621 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h289a71605f390793
  57:     0x7fb31383c403 - rustc_data_structures::stack::ensure_sufficient_stack::h4b6e02134b2da06d
  58:     0x7fb312df411d - rustc_query_system::query::plumbing::try_execute_query::hb362ed745d75a2d5
  59:     0x7fb312e5d0a9 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::mir_borrowck::hf27d489416d05e03
  60:     0x7fb312a9a8fc - rustc_typeck::collect::type_of::type_of::hca9404ffc74f128f
  61:     0x7fb3138bcf28 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::hc3aeb153f8ce060b
  62:     0x7fb31383d346 - rustc_data_structures::stack::ensure_sufficient_stack::h592a81c1112cc4b9
  63:     0x7fb312de2015 - rustc_query_system::query::plumbing::try_execute_query::h4d6ef156dd398725
  64:     0x7fb312e5a8f6 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::type_of::h407cb8e429259267
  65:     0x7fb3130dde58 - rustc_trait_selection::traits::select::confirmation::<impl rustc_trait_selection::traits::select::SelectionContext>::confirm_candidate::h7b30d6040a1a88cd
  66:     0x7fb3130e0405 - rustc_trait_selection::traits::select::SelectionContext::select::h44ccb99a80e00d65
  67:     0x7fb3130adbbe - rustc_trait_selection::traits::fulfill::FulfillProcessor::process_trait_obligation::h656af21652ddab63
  68:     0x7fb3130ac8c6 - rustc_trait_selection::traits::fulfill::FulfillProcessor::progress_changed_obligations::ha0aa535d762060d9
  69:     0x7fb3130c444b - rustc_data_structures::obligation_forest::ObligationForest<O>::process_obligations::h9b19112ccc099349
  70:     0x7fb3130abe4c - rustc_trait_selection::traits::fulfill::FulfillmentContext::select::h5feaa97543394f08
  71:     0x7fb3130ac5b2 - <rustc_trait_selection::traits::fulfill::FulfillmentContext as rustc_infer::traits::engine::TraitEngine>::select_with_constness_where_possible::h3885ead61348d1bd
  72:     0x7fb3130ac320 - <rustc_trait_selection::traits::fulfill::FulfillmentContext as rustc_infer::traits::engine::TraitEngine>::select_all_with_constness_or_error::h09a89888f1392f5a
  73:     0x7fb3129f2ec1 - rustc_typeck::check::fn_ctxt::_impl::<impl rustc_typeck::check::fn_ctxt::FnCtxt>::select_all_obligations_or_error::hcea71775409d9908
  74:     0x7fb312a66676 - rustc_infer::infer::InferCtxtBuilder::enter::hb9b185b080f31781
  75:     0x7fb312a2ae03 - rustc_typeck::check::typeck::hd320344c890821b5
  76:     0x7fb313899ef1 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h387037e7d39cafef
  77:     0x7fb313841f43 - rustc_data_structures::stack::ensure_sufficient_stack::h9e9042d5d4151ec7
  78:     0x7fb312de3b65 - rustc_query_system::query::plumbing::try_execute_query::h5bbb54711c9a400d
  79:     0x7fb312e5ce49 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck::h32b5ef98ec541fe2
  80:     0x7fb311a5c0b4 - rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator::check::hccbb4f8b5324fe71
  81:     0x7fb311a5bc6b - <rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator as rustc_hir::intravisit::Visitor>::visit_impl_item::hcbae69c379d200c3
  82:     0x7fb311a5a6b5 - rustc_hir::intravisit::Visitor::visit_nested_impl_item::h72982611d2d7762b
  83:     0x7fb3119df782 - rustc_hir::intravisit::walk_item::h5b06274924ecd69a
  84:     0x7fb312a9c268 - rustc_typeck::collect::type_of::type_of::hca9404ffc74f128f
  85:     0x7fb3138bcf28 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::hc3aeb153f8ce060b
  86:     0x7fb31383d346 - rustc_data_structures::stack::ensure_sufficient_stack::h592a81c1112cc4b9
  87:     0x7fb312de2015 - rustc_query_system::query::plumbing::try_execute_query::h4d6ef156dd398725
  88:     0x7fb312e5a8f6 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::type_of::h407cb8e429259267
  89:     0x7fb312aa84c5 - rustc_typeck::check::check::check_item_type::hb275e936432d1428
  90:     0x7fb312a8b035 - rustc_middle::hir::map::Map::visit_item_likes_in_module::h2d01a6d23ae7f6ed
  91:     0x7fb31359113c - rustc_typeck::check::check::check_mod_item_types::h940e5223b070e957
  92:     0x7fb3138b8a31 - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::hb80f32bec4db4096
  93:     0x7fb313848a03 - rustc_data_structures::stack::ensure_sufficient_stack::hfa8581b71108d87a
  94:     0x7fb312ddd6f9 - rustc_query_system::query::plumbing::try_execute_query::h3f20ac888ca305a2
  95:     0x7fb3138582e5 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::check_mod_item_types::he4d05ba02aacdd3d
  96:     0x7fb313581798 - rustc_middle::hir::map::Map::for_each_module::hb81c3a6c8e183c36
  97:     0x7fb3135cade0 - rustc_typeck::check_crate::h7feb9290e351ef2e
  98:     0x7fb313291870 - rustc_interface::passes::analysis::hb918b02982537851
  99:     0x7fb313898a6f - rustc_query_system::dep_graph::graph::DepGraph<K>::with_task::h347feb22cb0d1ecf
 100:     0x7fb31383c539 - rustc_data_structures::stack::ensure_sufficient_stack::h4b6ffa4a2dfebaef
 101:     0x7fb313780dbb - rustc_query_system::query::plumbing::try_execute_query::h784269645558384c
 102:     0x7fb3138568d2 - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::analysis::ha8ab0b7748e9a5d1
 103:     0x7fb313288749 - rustc_interface::passes::QueryContext::enter::h805836b6c10e023c
 104:     0x7fb31326f724 - rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter::hded9061889acb733
 105:     0x7fb31325ca45 - rustc_span::with_source_map::hce3a664e96079636
 106:     0x7fb31326f04c - scoped_tls::ScopedKey<T>::set::h033dd5b45ac9d9cd
 107:     0x7fb31325da7d - std::sys_common::backtrace::__rust_begin_short_backtrace::hc72d766e7b5b424b
 108:     0x7fb31325b2e5 - core::ops::function::FnOnce::call_once{{vtable.shim}}::hdbb85447b47f9f9d
 109:     0x7fb310f06e33 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h59eef3b9c8a82350
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/alloc/src/boxed.rs:1636:9
 110:     0x7fb310f06e33 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hb5bbe017c347469c
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/alloc/src/boxed.rs:1636:9
 111:     0x7fb310f06e33 - std::sys::unix::thread::Thread::new::thread_start::h62931528f61e35f5
                               at /rustc/ac2d9fc509e36d1b32513744adf58c34bcc4f43c/library/std/src/sys/unix/thread.rs:106:17
 112:     0x7fb310e1c259 - start_thread
 113:     0x7fb310d315e3 - __GI___clone
 114:                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 1.57.0-nightly (ac2d9fc50 2021-09-21) running on x86_64-unknown-linux-gnu

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

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

query stack during panic:
#0 [typeck] type-checking `changeset::storage::do_search_2`
#1 [mir_built] building MIR for `changeset::storage::do_search_2`
#2 [unsafety_check_result] unsafety-checking `changeset::storage::do_search_2`
#3 [mir_const] processing MIR for `changeset::storage::do_search_2`
#4 [mir_promoted] processing `changeset::storage::do_search_2`
#5 [mir_borrowck] borrow-checking `changeset::storage::do_search_2`
#6 [type_of] computing type of `changeset::storage::do_search_2::{opaque#0}`
#7 [typeck] type-checking `changeset::storage::<impl at src/changeset/storage.rs:7:1: 76:2>::find`
#8 [type_of] computing type of `changeset::storage::<impl at src/changeset/storage.rs:7:1: 76:2>::EncodedStream::{opaque#0}`
#9 [check_mod_item_types] checking item types in module `changeset::storage`
#10 [analysis] running analysis passes on this crate
end of query stack

[RobinMarchart]

I might have found another more minimal example that panics at the same place.
although this piece of code is syntactically wrong, it probably should not crash the compiler

#![feature(fn_traits,unboxed_closures)]
struct Func{}
impl Fn(&str)->bool for Func{
    extern "rust-call" fn call(&self, args: Args) -> Self::Output {
        todo!()
    }
}

playground link

[Alexendoo]

Fixed by #95085