Closed
Description
I tried to write a generic async wrapper for something similar to tokio_reactor::PollEvented that calls poll_..., clear_... and yield depending on the io::Result of an operation and got the error mentioned in the subject.
I managed to reduce the code triggering it to this:
#![feature(async_await,futures_api,await_macro,generators)]
pub struct Foo;
impl Foo {
async fn with<'a, F, R>(&'a self, f: F) -> R
where
F: Fn() -> R + 'a,
{
loop {
match f() {
_ => yield,
}
}
}
pub async fn run<'a>(&'a self, data: &'a [u8])
{
await!(self.with(move || {
println!("{:p}", data);
}))
}
}
fn main() {
}Probably related to #53989.
Full error message:
error: internal compiler error: src/librustc/infer/region_constraints/mod.rs:683: cannot relate bound region: ReLateBound(DebruijnIndex(1), BrAnon(2)) <= '_#1r
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:538:9
stack backtrace:
0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:72
2: std::panicking::default_hook::{{closure}}
at src/libstd/sys_common/backtrace.rs:60
at src/libstd/panicking.rs:210
3: std::panicking::default_hook
at src/libstd/panicking.rs:225
4: rustc::util::common::panic_hook
5: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:492
6: std::panicking::begin_panic
7: rustc_errors::Handler::span_bug
8: rustc::util::bug::opt_span_bug_fmt::{{closure}}
9: rustc::ty::context::tls::with_opt::{{closure}}
10: rustc::ty::context::tls::with_context_opt
11: rustc::ty::context::tls::with_opt
12: rustc::util::bug::opt_span_bug_fmt
13: rustc::util::bug::span_bug_fmt
14: rustc::infer::region_constraints::RegionConstraintCollector::make_subregion
15: rustc::infer::region_constraints::RegionConstraintCollector::make_eqregion
16: <rustc::infer::equate::Equate<'combine, 'infcx, 'gcx, 'tcx> as rustc::ty::relate::TypeRelation<'infcx, 'gcx, 'tcx>>::regions
17: rustc::ty::relate::super_relate_tys
18: rustc::infer::combine::<impl rustc::infer::InferCtxt<'infcx, 'gcx, 'tcx>>::super_combine_tys
19: <rustc::infer::equate::Equate<'combine, 'infcx, 'gcx, 'tcx> as rustc::ty::relate::TypeRelation<'infcx, 'gcx, 'tcx>>::tys
20: <rustc::ty::subst::Kind<'tcx> as rustc::ty::relate::Relate<'tcx>>::relate
21: <smallvec::SmallVec<A> as core::iter::traits::FromIterator<<A as smallvec::Array>::Item>>::from_iter
22: <I as rustc::ty::context::InternAs<[T], R>>::intern_with
23: <rustc::ty::sty::TraitRef<'tcx> as rustc::ty::relate::Relate<'tcx>>::relate
24: rustc::infer::InferCtxt::commit_if_ok
25: rustc::traits::select::SelectionContext::match_impl
26: rustc::infer::InferCtxt::probe
27: rustc::ty::trait_def::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::for_each_relevant_impl
28: rustc::traits::select::SelectionContext::assemble_candidates_from_impls
29: rustc::traits::select::SelectionContext::assemble_candidates
30: rustc::traits::select::SelectionContext::candidate_from_obligation_no_cache
31: rustc::ty::context::tls::with_context
32: rustc::dep_graph::graph::DepGraph::with_anon_task
33: rustc::traits::select::SelectionContext::candidate_from_obligation
34: rustc::traits::select::SelectionContext::evaluate_stack
35: rustc::ty::context::tls::with_context
36: rustc::dep_graph::graph::DepGraph::with_anon_task
37: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
38: rustc::infer::InferCtxt::probe
39: rustc::traits::select::SelectionContext::evaluate_stack
40: rustc::ty::context::tls::with_context
41: rustc::dep_graph::graph::DepGraph::with_anon_task
42: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
43: rustc::infer::InferCtxt::probe
44: rustc::traits::select::SelectionContext::evaluate_stack
45: rustc::ty::context::tls::with_context
46: rustc::dep_graph::graph::DepGraph::with_anon_task
47: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
48: rustc::infer::InferCtxt::probe
49: rustc::traits::select::SelectionContext::evaluate_stack
50: rustc::ty::context::tls::with_context
51: rustc::dep_graph::graph::DepGraph::with_anon_task
52: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
53: rustc::infer::InferCtxt::probe
54: rustc::traits::select::SelectionContext::evaluate_stack
55: rustc::ty::context::tls::with_context
56: rustc::dep_graph::graph::DepGraph::with_anon_task
57: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
58: rustc::infer::InferCtxt::probe
59: rustc::traits::select::SelectionContext::evaluate_stack
60: rustc::ty::context::tls::with_context
61: rustc::dep_graph::graph::DepGraph::with_anon_task
62: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
63: rustc::infer::InferCtxt::probe
64: rustc::traits::select::SelectionContext::evaluate_stack
65: rustc::ty::context::tls::with_context
66: rustc::dep_graph::graph::DepGraph::with_anon_task
67: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
68: rustc::infer::InferCtxt::probe
69: rustc::traits::select::SelectionContext::evaluate_stack
70: rustc::ty::context::tls::with_context
71: rustc::dep_graph::graph::DepGraph::with_anon_task
72: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
73: rustc::infer::InferCtxt::probe
74: rustc::traits::select::SelectionContext::evaluate_stack
75: rustc::ty::context::tls::with_context
76: rustc::dep_graph::graph::DepGraph::with_anon_task
77: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
78: rustc::traits::select::SelectionContext::evaluate_obligation_recursively
79: rustc::ty::context::tls::with_related_context
80: rustc_traits::evaluate_obligation::evaluate_obligation
81: rustc::ty::query::__query_compute::evaluate_obligation
82: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::evaluate_obligation<'tcx>>::compute
83: rustc::ty::context::tls::with_context
84: rustc::dep_graph::graph::DepGraph::with_task_impl
85: rustc::ty::context::tls::with_related_context
86: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
87: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::try_get_with
88: rustc::traits::query::evaluate_obligation::<impl rustc::infer::InferCtxt<'cx, 'gcx, 'tcx>>::evaluate_obligation
89: rustc::traits::query::evaluate_obligation::<impl rustc::infer::InferCtxt<'cx, 'gcx, 'tcx>>::evaluate_obligation_no_overflow
90: rustc::traits::type_known_to_meet_bound
91: rustc::ty::context::tls::with_related_context
92: rustc::infer::InferCtxtBuilder::enter
93: rustc::ty::util::is_freeze_raw
94: rustc::ty::query::__query_compute::is_freeze_raw
95: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::is_freeze_raw<'tcx>>::compute
96: rustc::ty::context::tls::with_context
97: rustc::dep_graph::graph::DepGraph::with_task_impl
98: rustc::ty::context::tls::with_related_context
99: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `[static generator@src/main.rs:18:2: 22:3 self:&Foo, data:&[u8] for<'r, 's, 't0> {impl std::future::Future, ()}]: std::marker::Freeze`
#1 [is_freeze_raw] computing whether `[static generator@src/main.rs:18:2: 22:3 self:&'a Foo, data:&'a [u8] for<'r, 's, 't0> {impl std::future::Future, ()}]` is freeze
#2 [mir_validated] processing `Foo::run::{{closure}}`
#3 [mir_borrowck] processing `Foo::run::{{closure}}`
end of query stack
error: aborting due to previous error
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 1.33.0-nightly (2d3e909e4 2018-12-22) running on x86_64-unknown-linux-gnu
note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin
note: some of the compiler flags provided by cargo are hidden