ICE: could not fully normalize fn with -Z mir-opt-level=3

[matthiaskrgr]

rustc src/test/ui/issues/issue-38033.rs -Zmir-opt-level=3

file:

// run-pass
use std::marker;
use std::mem;

fn main() {
    let workers = (0..0).map(|_| result::<u32, ()>());
    drop(join_all(workers).poll());
}

trait Future {
    type Item;
    type Error;

    fn poll(&mut self) -> Result<Self::Item, Self::Error>;
}

trait IntoFuture {
    type Future: Future<Item=Self::Item, Error=Self::Error>;
    type Item;
    type Error;

    fn into_future(self) -> Self::Future;
}

impl<F: Future> IntoFuture for F {
    type Future = F;
    type Item = F::Item;
    type Error = F::Error;

    fn into_future(self) -> F {
        self
    }
}

struct FutureResult<T, E> {
    _inner: marker::PhantomData<(T, E)>,
}

fn result<T, E>() -> FutureResult<T, E> {
    loop {}
}

impl<T, E> Future for FutureResult<T, E> {
    type Item = T;
    type Error = E;

    fn poll(&mut self) -> Result<T, E> {
        loop {}
    }
}

struct JoinAll<I>
    where I: IntoIterator,
          I::Item: IntoFuture,
{
    elems: Vec<<I::Item as IntoFuture>::Item>,
}

fn join_all<I>(_: I) -> JoinAll<I>
    where I: IntoIterator,
          I::Item: IntoFuture,
{
    JoinAll { elems: vec![] }
}

impl<I> Future for JoinAll<I>
    where I: IntoIterator,
          I::Item: IntoFuture,
{
    type Item = Vec<<I::Item as IntoFuture>::Item>;
    type Error = <I::Item as IntoFuture>::Error;

    fn poll(&mut self) -> Result<Self::Item, Self::Error> {
        let elems = mem::replace(&mut self.elems, Vec::new());
        Ok(elems.into_iter().map(|e| {
            e
        }).collect::<Vec<_>>())
    }
}

error: internal compiler error: src/librustc_traits/normalize_erasing_regions.rs:34: could not fully normalize `fn() -> alloc::raw_vec::RawVec<<<I as std::iter::IntoIterator>::Item as IntoFuture>::Item> {alloc::raw_vec::RawVec::<<<I as std::iter::IntoIterator>::Item as IntoFuture>::Item>::new}`

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:891:9
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:77
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1057
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1426
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:195
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:215
  10: <alloc::boxed::Box<F> as core::ops::function::Fn<A>>::call
             at /home/matthias/vcs/github/rust_debug_assertions/src/liballoc/boxed.rs:1029
  11: rustc_driver::report_ice
             at src/librustc_driver/lib.rs:1160
  12: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
  13: std::panicking::begin_panic
             at /home/matthias/vcs/github/rust_debug_assertions/src/libstd/panicking.rs:401
  14: rustc_errors::HandlerInner::bug
             at src/librustc_errors/lib.rs:891
  15: rustc_errors::Handler::bug
             at src/librustc_errors/lib.rs:651
  16: rustc::util::bug::opt_span_bug_fmt::{{closure}}
             at src/librustc/util/bug.rs:36
  17: rustc::ty::context::tls::with_opt::{{closure}}
             at src/librustc/ty/context.rs:1875
  18: rustc::ty::context::tls::with_context_opt
             at src/librustc/ty/context.rs:1827
  19: rustc::ty::context::tls::with_opt
             at src/librustc/ty/context.rs:1875
  20: rustc::util::bug::opt_span_bug_fmt
             at src/librustc/util/bug.rs:32
  21: rustc::util::bug::bug_fmt
             at src/librustc/util/bug.rs:12
  22: rustc_traits::normalize_erasing_regions::normalize_ty_after_erasing_regions::{{closure}}
             at src/librustc_traits/normalize_erasing_regions.rs:34
  23: rustc::infer::InferCtxtBuilder::enter::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/infer/mod.rs:535
  24: rustc::ty::context::GlobalCtxt::enter_local::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1545
  25: rustc::ty::context::tls::enter_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
  26: rustc::ty::context::tls::set_tlv
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1699
  27: rustc::ty::context::tls::enter_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
  28: rustc::ty::context::GlobalCtxt::enter_local::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1545
  29: rustc::ty::context::tls::with_related_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1854
  30: rustc::ty::context::tls::with_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
  31: rustc::ty::context::tls::with_context_opt
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1827
  32: rustc::ty::context::tls::with_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
  33: rustc::ty::context::tls::with_related_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1851
  34: rustc::ty::context::GlobalCtxt::enter_local
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1537
  35: rustc::infer::InferCtxtBuilder::enter
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/infer/mod.rs:534
  36: rustc_traits::normalize_erasing_regions::normalize_ty_after_erasing_regions
             at src/librustc_traits/normalize_erasing_regions.rs:19
  37: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::normalize_ty_after_erasing_regions>::compute::{{closure}}
             at src/librustc/ty/query/plumbing.rs:971
  38: rustc::ty::query::__query_compute::normalize_ty_after_erasing_regions
             at src/librustc/ty/query/plumbing.rs:922
  39: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::normalize_ty_after_erasing_regions>::compute
             at src/librustc/ty/query/plumbing.rs:963
  40: rustc::dep_graph::graph::DepGraph::with_task_impl
             at src/librustc/dep_graph/graph.rs:325
  41: rustc::dep_graph::graph::DepGraph::with_task
             at src/librustc/dep_graph/graph.rs:193
  42: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}}
             at src/librustc/ty/query/plumbing.rs:543
  43: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}
             at src/librustc/ty/query/plumbing.rs:267
  44: rustc::ty::context::tls::enter_context::{{closure}}
             at src/librustc/ty/context.rs:1766
  45: rustc::ty::context::tls::set_tlv
             at src/librustc/ty/context.rs:1699
  46: rustc::ty::context::tls::enter_context
             at src/librustc/ty/context.rs:1766
  47: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}
             at src/librustc/ty/query/plumbing.rs:267
  48: rustc::ty::context::tls::with_related_context::{{closure}}
             at src/librustc/ty/context.rs:1854
  49: rustc::ty::context::tls::with_context::{{closure}}
             at src/librustc/ty/context.rs:1838
  50: rustc::ty::context::tls::with_context_opt
             at src/librustc/ty/context.rs:1827
  51: rustc::ty::context::tls::with_context
             at src/librustc/ty/context.rs:1838
  52: rustc::ty::context::tls::with_related_context
             at src/librustc/ty/context.rs:1851
  53: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query
             at src/librustc/ty/query/plumbing.rs:256
  54: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}
             at src/librustc/ty/query/plumbing.rs:533
  55: rustc::ty::query::plumbing::with_diagnostics
             at src/librustc/ty/query/plumbing.rs:201
  56: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job
             at src/librustc/ty/query/plumbing.rs:532
  57: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
             at src/librustc/ty/query/plumbing.rs:369
  58: rustc::ty::query::TyCtxtAt::normalize_ty_after_erasing_regions
             at src/librustc/ty/query/plumbing.rs:1048
  59: rustc::ty::query::<impl rustc::ty::context::TyCtxt>::normalize_ty_after_erasing_regions
             at src/librustc/ty/query/plumbing.rs:1040
  60: <rustc::traits::query::normalize_erasing_regions::NormalizeAfterErasingRegionsFolder as rustc::ty::fold::TypeFolder>::fold_ty
             at src/librustc/traits/query/normalize_erasing_regions.rs:76
  61: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::fold_with
             at src/librustc/ty/structural_impls.rs:929
  62: rustc::traits::query::normalize_erasing_regions::<impl rustc::ty::context::TyCtxt>::normalize_erasing_regions
             at src/librustc/traits/query/normalize_erasing_regions.rs:36
  63: rustc::traits::codegen::<impl rustc::ty::context::TyCtxt>::subst_and_normalize_erasing_regions
             at src/librustc/traits/codegen/mod.rs:100
  64: rustc::ty::instance::Instance::ty
             at src/librustc/ty/instance.rs:67
  65: rustc_mir::interpret::terminator::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_fn_call
             at src/librustc_mir/interpret/terminator.rs:208
  66: rustc_mir::interpret::terminator::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_terminator
             at src/librustc_mir/interpret/terminator.rs:73
  67: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::terminator
             at src/librustc_mir/interpret/step.rs:284
  68: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::step
             at src/librustc_mir/interpret/step.rs:72
  69: rustc_mir::interpret::step::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::run
             at src/librustc_mir/interpret/step.rs:34
  70: rustc_mir::const_eval::eval_body_using_ecx
             at src/librustc_mir/const_eval.rs:167
  71: rustc_mir::const_eval::const_eval_raw_provider::{{closure}}
             at src/librustc_mir/const_eval.rs:713
  72: core::result::Result<T,E>::and_then
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/result.rs:720
  73: rustc_mir::const_eval::const_eval_raw_provider
             at src/librustc_mir/const_eval.rs:713
  74: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::const_eval_raw>::compute::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:971
  75: rustc::ty::query::__query_compute::const_eval_raw
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:922
  76: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::const_eval_raw>::compute
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:963
  77: rustc::dep_graph::graph::DepGraph::with_task_impl
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:325
  78: rustc::dep_graph::graph::DepGraph::with_task
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:193
  79: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:543
  80: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
  81: rustc::ty::context::tls::enter_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
  82: rustc::ty::context::tls::set_tlv
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1699
  83: rustc::ty::context::tls::enter_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
  84: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
  85: rustc::ty::context::tls::with_related_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1854
  86: rustc::ty::context::tls::with_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
  87: rustc::ty::context::tls::with_context_opt
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1827
  88: rustc::ty::context::tls::with_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
  89: rustc::ty::context::tls::with_related_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1851
  90: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:256
  91: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:533
  92: rustc::ty::query::plumbing::with_diagnostics
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:201
  93: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:532
  94: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:369
  95: rustc::ty::query::TyCtxtAt::const_eval_raw
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:1048
  96: rustc_mir::interpret::eval_context::InterpCx<M>::const_eval_raw
             at src/librustc_mir/interpret/eval_context.rs:771
  97: rustc_mir::interpret::operand::<impl rustc_mir::interpret::eval_context::InterpCx<M>>::eval_const_to_op
             at src/librustc_mir/interpret/operand.rs:581
  98: rustc_mir::transform::const_prop::ConstPropagator::eval_constant
             at src/librustc_mir/transform/const_prop.rs:414
  99: <rustc_mir::transform::const_prop::ConstPropagator as rustc::mir::visit::MutVisitor>::visit_constant
             at src/librustc_mir/transform/const_prop.rs:751
 100: rustc::mir::visit::MutVisitor::super_operand
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:678
 101: rustc::mir::visit::MutVisitor::visit_operand
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:141
 102: rustc::mir::visit::MutVisitor::super_rvalue
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:0
 103: rustc::mir::visit::MutVisitor::visit_rvalue
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:135
 104: rustc::mir::visit::MutVisitor::super_assign
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:423
 105: rustc::mir::visit::MutVisitor::visit_assign
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:111
 106: rustc::mir::visit::MutVisitor::super_statement
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:358
 107: <rustc_mir::transform::const_prop::ConstPropagator as rustc::mir::visit::MutVisitor>::visit_statement
             at src/librustc_mir/transform/const_prop.rs:801
 108: rustc::mir::visit::MutVisitor::super_basic_block_data
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:322
 109: rustc::mir::visit::MutVisitor::visit_basic_block_data
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:93
 110: rustc::mir::visit::MutVisitor::super_body
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:275
 111: rustc::mir::visit::MutVisitor::visit_body
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/mir/visit.rs:87
 112: <rustc_mir::transform::const_prop::ConstProp as rustc_mir::transform::MirPass>::run_pass
             at src/librustc_mir/transform/const_prop.rs:97
 113: rustc_mir::transform::run_passes::{{closure}}
             at src/librustc_mir/transform/mod.rs:171
 114: rustc_mir::transform::run_passes
             at src/librustc_mir/transform/mod.rs:178
 115: rustc_mir::transform::run_optimization_passes
             at src/librustc_mir/transform/mod.rs:273
 116: rustc_mir::transform::optimized_mir
             at src/librustc_mir/transform/mod.rs:343
 117: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:971
 118: rustc::ty::query::__query_compute::optimized_mir
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:922
 119: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:963
 120: rustc::dep_graph::graph::DepGraph::with_task_impl
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:325
 121: rustc::dep_graph::graph::DepGraph::with_task
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:193
 122: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:543
 123: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
 124: rustc::ty::context::tls::enter_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 125: rustc::ty::context::tls::set_tlv
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1699
 126: rustc::ty::context::tls::enter_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 127: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
 128: rustc::ty::context::tls::with_related_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1854
 129: rustc::ty::context::tls::with_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
 130: rustc::ty::context::tls::with_context_opt
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1827
 131: rustc::ty::context::tls::with_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
 132: rustc::ty::context::tls::with_related_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1851
 133: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:256
 134: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:533
 135: rustc::ty::query::plumbing::with_diagnostics
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:201
 136: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:532
 137: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:369
 138: rustc::ty::query::TyCtxtAt::optimized_mir
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:1048
 139: rustc::ty::query::<impl rustc::ty::context::TyCtxt>::optimized_mir
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:1040
 140: rustc_mir::transform::inline::Inliner::run_pass
             at src/librustc_mir/transform/inline.rs:108
 141: <rustc_mir::transform::inline::Inline as rustc_mir::transform::MirPass>::run_pass
             at src/librustc_mir/transform/inline.rs:43
 142: rustc_mir::transform::run_passes::{{closure}}
             at src/librustc_mir/transform/mod.rs:171
 143: rustc_mir::transform::run_passes
             at src/librustc_mir/transform/mod.rs:178
 144: rustc_mir::transform::run_optimization_passes
             at src/librustc_mir/transform/mod.rs:273
 145: rustc_mir::transform::optimized_mir
             at src/librustc_mir/transform/mod.rs:343
 146: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::optimized_mir>::compute
             at src/librustc/ty/query/plumbing.rs:963
 147: rustc::dep_graph::graph::DepGraph::with_task_impl
             at src/librustc/dep_graph/graph.rs:325
 148: rustc::dep_graph::graph::DepGraph::with_task
             at src/librustc/dep_graph/graph.rs:193
 149: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}}
             at src/librustc/ty/query/plumbing.rs:543
 150: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}
             at src/librustc/ty/query/plumbing.rs:267
 151: rustc::ty::context::tls::enter_context::{{closure}}
             at src/librustc/ty/context.rs:1766
 152: rustc::ty::context::tls::set_tlv
             at src/librustc/ty/context.rs:1699
 153: rustc::ty::context::tls::enter_context
             at src/librustc/ty/context.rs:1766
 154: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}
             at src/librustc/ty/query/plumbing.rs:267
 155: rustc::ty::context::tls::with_related_context::{{closure}}
             at src/librustc/ty/context.rs:1854
 156: rustc::ty::context::tls::with_context::{{closure}}
             at src/librustc/ty/context.rs:1838
 157: rustc::ty::context::tls::with_context_opt
             at src/librustc/ty/context.rs:1827
 158: rustc::ty::context::tls::with_context
             at src/librustc/ty/context.rs:1838
 159: rustc::ty::context::tls::with_related_context
             at src/librustc/ty/context.rs:1851
 160: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query
             at src/librustc/ty/query/plumbing.rs:256
 161: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}
             at src/librustc/ty/query/plumbing.rs:533
 162: rustc::ty::query::plumbing::with_diagnostics
             at src/librustc/ty/query/plumbing.rs:201
 163: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job
             at src/librustc/ty/query/plumbing.rs:532
 164: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
             at src/librustc/ty/query/plumbing.rs:369
 165: rustc::ty::query::TyCtxtAt::optimized_mir
             at src/librustc/ty/query/plumbing.rs:1048
 166: rustc::ty::query::<impl rustc::ty::context::TyCtxt>::optimized_mir
             at src/librustc/ty/query/plumbing.rs:1040
 167: rustc::ty::<impl rustc::ty::context::TyCtxt>::instance_mir
             at src/librustc/ty/mod.rs:2955
 168: rustc_mir::monomorphize::collector::collect_neighbours
             at src/librustc_mir/monomorphize/collector.rs:1221
 169: rustc_mir::monomorphize::collector::collect_items_rec
             at src/librustc_mir/monomorphize/collector.rs:381
 170: rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}}::{{closure}}
             at src/librustc_mir/monomorphize/collector.rs:306
 171: core::iter::traits::iterator::Iterator::for_each::call::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/iter/traits/iterator.rs:652
 172: core::iter::traits::iterator::Iterator::fold::ok::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/iter/traits/iterator.rs:1900
 173: core::iter::traits::iterator::Iterator::try_fold
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/iter/traits/iterator.rs:1776
 174: core::iter::traits::iterator::Iterator::fold
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/iter/traits/iterator.rs:1903
 175: core::iter::traits::iterator::Iterator::for_each
             at /home/matthias/vcs/github/rust_debug_assertions/src/libcore/iter/traits/iterator.rs:655
 176: rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}}
             at src/librustc_mir/monomorphize/collector.rs:304
 177: rustc::util::common::time_ext
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:54
 178: rustc::util::common::time
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:46
 179: rustc_mir::monomorphize::collector::collect_crate_mono_items
             at src/librustc_mir/monomorphize/collector.rs:303
 180: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items::{{closure}}
             at src/librustc_mir/monomorphize/partitioning.rs:870
 181: rustc::util::common::time_ext
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:54
 182: rustc::util::common::time
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:46
 183: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
             at src/librustc_mir/monomorphize/partitioning.rs:869
 184: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_and_partition_mono_items>::compute::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:971
 185: rustc::ty::query::__query_compute::collect_and_partition_mono_items
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:922
 186: rustc::dep_graph::graph::DepGraph::with_task_impl
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:325
 187: rustc::dep_graph::graph::DepGraph::with_eval_always_task
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/dep_graph/graph.rs:372
 188: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:535
 189: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
 190: rustc::ty::context::tls::enter_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 191: rustc::ty::context::tls::set_tlv
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1699
 192: rustc::ty::context::tls::enter_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 193: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:267
 194: rustc::ty::context::tls::with_related_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1854
 195: rustc::ty::context::tls::with_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
 196: rustc::ty::context::tls::with_context_opt
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1827
 197: rustc::ty::context::tls::with_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1838
 198: rustc::ty::context::tls::with_related_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1851
 199: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::start_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:256
 200: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:533
 201: rustc::ty::query::plumbing::with_diagnostics
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:201
 202: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::force_query_with_job
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:532
 203: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:369
 204: rustc::ty::query::TyCtxtAt::collect_and_partition_mono_items
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:1048
 205: rustc::ty::query::<impl rustc::ty::context::TyCtxt>::collect_and_partition_mono_items
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/query/plumbing.rs:1040
 206: rustc_codegen_ssa::base::codegen_crate
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_codegen_ssa/base.rs:532
 207: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_utils::codegen_backend::CodegenBackend>::codegen_crate
             at src/librustc_codegen_llvm/lib.rs:263
 208: rustc_interface::passes::start_codegen::{{closure}}
             at src/librustc_interface/passes.rs:985
 209: rustc::util::common::time_ext
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:54
 210: rustc::util::common::time
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/util/common.rs:46
 211: rustc_interface::passes::start_codegen
             at src/librustc_interface/passes.rs:983
 212: rustc_interface::queries::Queries::ongoing_codegen::{{closure}}::{{closure}}
             at src/librustc_interface/queries.rs:282
 213: rustc_interface::passes::QueryContext::enter::{{closure}}
             at src/librustc_interface/passes.rs:711
 214: rustc::ty::context::tls::enter_global::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1789
 215: rustc::ty::context::tls::enter_context::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 216: rustc::ty::context::tls::set_tlv
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1699
 217: rustc::ty::context::tls::enter_context
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1766
 218: rustc::ty::context::tls::enter_global
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1789
 219: rustc_interface::passes::QueryContext::enter
             at src/librustc_interface/passes.rs:711
 220: rustc_interface::queries::Queries::ongoing_codegen::{{closure}}
             at src/librustc_interface/queries.rs:276
 221: rustc_interface::queries::Query<T>::compute
             at src/librustc_interface/queries.rs:34
 222: rustc_interface::queries::Queries::ongoing_codegen
             at src/librustc_interface/queries.rs:274
 223: rustc_driver::run_compiler::{{closure}}::{{closure}}
             at src/librustc_driver/lib.rs:404
 224: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/queries.rs:332
 225: rustc_driver::run_compiler::{{closure}}
             at src/librustc_driver/lib.rs:295
 226: rustc_interface::interface::run_compiler_in_existing_thread_pool
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/interface.rs:184
 227: rustc_interface::interface::run_compiler::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/interface.rs:193
 228: rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}}::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/util.rs:154
 229: rustc::ty::context::tls::with_thread_locals::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1755
 230: std::thread::local::LocalKey<T>::try_with
             at /home/matthias/vcs/github/rust_debug_assertions/src/libstd/thread/local.rs:262
 231: std::thread::local::LocalKey<T>::with
             at /home/matthias/vcs/github/rust_debug_assertions/src/libstd/thread/local.rs:239
 232: rustc::ty::context::tls::with_thread_locals::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1747
 233: std::thread::local::LocalKey<T>::try_with
             at /home/matthias/vcs/github/rust_debug_assertions/src/libstd/thread/local.rs:262
 234: std::thread::local::LocalKey<T>::with
             at /home/matthias/vcs/github/rust_debug_assertions/src/libstd/thread/local.rs:239
 235: rustc::ty::context::tls::with_thread_locals
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc/ty/context.rs:1739
 236: rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/util.rs:154
 237: scoped_tls::ScopedKey<T>::set
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
 238: rustc_interface::util::spawn_thread_pool::{{closure}}::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/util.rs:150
 239: scoped_tls::ScopedKey<T>::set
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
 240: syntax::with_globals::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/libsyntax/lib.rs:60
 241: scoped_tls::ScopedKey<T>::set
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/scoped-tls-1.0.0/src/lib.rs:137
 242: syntax::with_globals
             at /home/matthias/vcs/github/rust_debug_assertions/src/libsyntax/lib.rs:60
 243: rustc_interface::util::spawn_thread_pool::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/util.rs:149
 244: rustc_interface::util::scoped_thread::{{closure}}
             at /home/matthias/vcs/github/rust_debug_assertions/src/librustc_interface/util.rs:126
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 1.42.0-dev running on x86_64-unknown-linux-gnu

note: compiler flags: -Z mir-opt-level=3

query stack during panic:
#0 [normalize_ty_after_erasing_regions] normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All, def_id: None }, value: fn() -> alloc::raw_vec::RawVec<<<I as std::iter::IntoIterator>::Item as IntoFuture>::Item> {alloc::raw_vec::RawVec::<<<I as std::iter::IntoIterator>::Item as IntoFuture>::Item>::new} }`
#1 [const_eval_raw] const-evaluating `alloc::raw_vec::RawVec::<T>::NEW`
#2 [optimized_mir] processing `<JoinAll<I> as Future>::poll`
#3 [optimized_mir] processing `main`
#4 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: aborting due to previous error

rustc @ bbf1372

[wesleywiser]

I spent some time today looking into this and I have a cut down version of the above test:

fn main() {
    join_all::<u32>();
}

trait Foo {
    type Item;
}

impl Foo for u32 {
    type Item = u8;
}

trait Bar {
    type Item2;
}

impl Bar for u8 {
    type Item2 = u64;
}

fn join_all<I>()
where I: Foo,
    I::Item: Bar
{
    Vec::<<I::Item as Bar>::Item2>::new(); // ICE occurs processing this line
}