Nightly error: internal compiler error: src/librustc_middle/ich/impls_ty.rs:94: StableHasher: unexpected region '_#10r

[benbromhead]

I tried this code (using cargo test to run the test):

use std::error::Error;
use async_trait::async_trait;

#[async_trait]
pub trait Transform2: Send + Sync {
    async fn transform(&self) -> Result<(), Box<dyn Error>>;
    fn get_name(&self) -> &'static str;
}

pub struct Printer {}

impl Printer {
    pub fn new() -> Printer {
        Printer{}
    }
}

#[async_trait]
impl Transform2 for Printer {
    async fn transform(&self) -> Result<(), Box<dyn Error>> {
        unimplemented!()
    }
    fn get_name(&self) -> &'static str {
        unimplemented!()
    }
}

#[tokio::test(threaded_scheduler)]
async fn test_compiler_script() -> Result<(), Box<dyn Error>> {
    let transforms: Vec<dyn Transform2> = vec![Printer::new()];

    return Ok(())
}

From my cargo.toml:

[dependencies]
async-trait = "0.1.30"
tokio = { version = "0.2.20", features = ["full", "macros"] }

I expected to see this happen:

This code should not compile and should produce some errors along the following (as it does on stable):

error[E0277]: the size for values of type `dyn Transform2` cannot be known at compilation time
  --> src/main.rs:30:21
   |
30 |     let transforms: Vec<dyn Transform2> = vec![Printer::new()];
   |                     ^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
   |
   = help: the trait `std::marker::Sized` is not implemented for `dyn Transform2`
   = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
   = note: required by `std::vec::Vec`
... [TRUNCATED for brevity]...

Instead, this happened:
error: internal compiler error: src/librustc_middle/ich/impls_ty.rs:94: StableHasher: unexpected region '_#10r
The rust compiler throws an internal error and panics.

Meta

rustc --version --verbose: rustc 1.45.0-nightly (46e85b432 2020-05-24) binary: rustc commit-hash: 46e85b4328fe18492894093c1092dfe509df4370 commit-date: 2020-05-24 host: x86_64-apple-darwin release: 1.45.0-nightly LLVM version: 10.0

Backtrace:

./.cargo/bin/cargo test --color=always --no-run --package dummy --bin dummy test_compiler_script -- --exact
   Compiling dummy v0.1.0 (.../CLionProjects/dummy)
error: internal compiler error: src/librustc_middle/ich/impls_ty.rs:94: StableHasher: unexpected region '_#10r

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:907:9
stack backtrace:
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: std::io::Write::write_fmt
   3: std::panicking::default_hook::{{closure}}
   4: std::panicking::default_hook
   5: rustc_driver::report_ice
   6: std::panicking::rust_panic_with_hook
   7: std::panicking::begin_panic
   8: rustc_errors::HandlerInner::bug
   9: rustc_errors::Handler::bug
  10: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
  11: rustc_middle::ty::context::tls::with_opt::{{closure}}
  12: rustc_middle::ty::context::tls::with_opt
  13: rustc_middle::util::bug::opt_span_bug_fmt
  14: rustc_middle::util::bug::bug_fmt
  15: rustc_middle::ich::impls_ty::<impl rustc_data_structures::stable_hasher::HashStable<rustc_middle::ich::hcx::StableHashingContext> for rustc_middle::ty::sty::RegionKind>::hash_stable
  16: <T as rustc_query_system::dep_graph::dep_node::DepNodeParams<Ctxt>>::to_fingerprint
  17: rustc_query_system::query::plumbing::get_query_impl
  18: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::error_reporting::suggestions::InferCtxtExt>::suggest_await_before_try
  19: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::error_reporting::InferCtxtExt>::report_selection_error
  20: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::error_reporting::InferCtxtExt>::report_fulfillment_errors
  21: rustc_typeck::check::FnCtxt::resolve_vars_with_obligations
  22: rustc_typeck::check::FnCtxt::structurally_resolved_type
  23: rustc_typeck::check::callee::<impl rustc_typeck::check::FnCtxt>::check_call
  24: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  25: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  26: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_coercable_to_type
  27: rustc_typeck::check::FnCtxt::check_decl_local
  28: rustc_typeck::check::FnCtxt::check_stmt
  29: rustc_typeck::check::FnCtxt::check_block_with_expected
  30: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  31: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  32: rustc_typeck::check::FnCtxt::check_block_with_expected
  33: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  34: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  35: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_return_expr
  36: rustc_typeck::check::check_fn
  37: rustc_typeck::check::closure::<impl rustc_typeck::check::FnCtxt>::check_expr_closure
  38: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  39: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  40: rustc_typeck::check::FnCtxt::check_argument_types
  41: rustc_typeck::check::callee::<impl rustc_typeck::check::FnCtxt>::confirm_builtin_call
  42: rustc_typeck::check::callee::<impl rustc_typeck::check::FnCtxt>::check_call
  43: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  44: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  45: rustc_typeck::check::FnCtxt::check_argument_types
  46: rustc_typeck::check::FnCtxt::check_method_argument_types
  47: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  48: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  49: rustc_typeck::check::FnCtxt::check_block_with_expected
  50: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_kind
  51: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_expr_with_expectation_and_needs
  52: rustc_typeck::check::expr::<impl rustc_typeck::check::FnCtxt>::check_return_expr
  53: rustc_typeck::check::check_fn
  54: rustc_middle::ty::context::GlobalCtxt::enter_local
  55: rustc_typeck::check::typeck_tables_of
  56: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_tables_of>::compute
  57: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  58: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  59: rustc_query_system::query::plumbing::get_query_impl
  60: rustc_typeck::check::typeck_tables_of
  61: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_tables_of>::compute
  62: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  63: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  64: rustc_query_system::query::plumbing::get_query_impl
  65: rustc_query_system::query::plumbing::ensure_query_impl
  66: rustc_typeck::check::typeck_item_bodies
  67: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_item_bodies>::compute
  68: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  69: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  70: rustc_query_system::query::plumbing::get_query_impl
  71: rustc_typeck::check_crate
  72: rustc_interface::passes::analysis
  73: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
  74: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  75: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  76: rustc_query_system::query::plumbing::get_query_impl
  77: rustc_middle::ty::context::tls::enter_global
  78: rustc_interface::interface::run_compiler_in_existing_thread_pool
  79: rustc_ast::attr::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.45.0-nightly (46e85b432 2020-05-24) running on x86_64-apple-darwin

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

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

query stack during panic:
#0 [typeck_tables_of] type-checking `test_compiler_script`
#1 [typeck_tables_of] type-checking `test_compiler_script::{{closure}}#0`
#2 [typeck_item_bodies] type-checking all item bodies
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

error: could not compile `dummy`.

[csmoe]

Duplicate of #72442