cargo check-invoked Rustc 10x slower since nightly-2019-10-03

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Starting nightly-2019-10-03, Rustc hangs forever is about 10x slower while building my project (Linux x86-64). It works fine on nightly-2019-10-01 and earlier versions. In between, nightly-2019-10-02 has an ICE.

I am only invoking cargo check.

See below for the ICE and the thread backtraces while rustc is hanging.

Rustc has an ICE on nightly-2019-10-02 ("fixed" in nightly-2019-10-03):

error: internal compiler error: src/librustc/ich/impls_ty.rs:100: StableHasher: unexpected region '_#0r

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:912:9
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/git.luolix.top-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/git.luolix.top-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:76
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:60
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1028
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1412
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:64
   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:196
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:210
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:477
  12: std::panicking::begin_panic
  13: rustc_errors::HandlerInner::bug
  14: rustc_errors::Handler::bug
  15: rustc::util::bug::opt_span_bug_fmt::{{closure}}
  16: rustc::ty::context::tls::with_opt::{{closure}}
  17: rustc::ty::context::tls::with_context_opt
  18: rustc::ty::context::tls::with_opt
  19: rustc::util::bug::opt_span_bug_fmt
  20: rustc::util::bug::bug_fmt
  21: rustc::ich::impls_ty::<impl rustc_data_structures::stable_hasher::HashStable<rustc::ich::hcx::StableHashingContext> for rustc::ty::sty::RegionKind>::hash_stable
  22: rustc::ty::sty::_DERIVE_rustc_data_structures_stable_hasher_HashStable_rustc_ich_StableHashingContext_ctx_FOR_TyKind::<impl rustc_data_structures::stable_hasher::HashStable<rustc::ich::hcx::StableHashingContext> for rustc::ty::sty::TyKind>::hash_stable
  23: <rustc::ty::context::TypeckTables as rustc_data_structures::stable_hasher::HashStable<rustc::ich::hcx::StableHashingContext>>::hash_stable
  24: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::hash_result
  25: rustc::dep_graph::graph::DepGraph::with_task_impl
  26: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  27: rustc::ty::query::__query_compute::typeck_tables_of
  28: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::typeck_tables_of>::compute
  29: rustc::dep_graph::graph::DepGraph::with_task_impl
  30: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  31: rustc_typeck::collect::checked_type_of
  32: rustc_typeck::collect::type_of
  33: rustc::ty::query::__query_compute::type_of
  34: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::type_of>::compute
  35: rustc::dep_graph::graph::DepGraph::with_task_impl
  36: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  37: rustc::hir::intravisit::walk_expr
  38: rustc::hir::intravisit::Visitor::visit_fn
  39: rustc::hir::intravisit::walk_impl_item
  40: rustc::hir::map::Map::visit_item_likes_in_module
  41: rustc_typeck::collect::collect_mod_item_types
  42: rustc::ty::query::__query_compute::collect_mod_item_types
  43: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::collect_mod_item_types>::compute
  44: rustc::dep_graph::graph::DepGraph::with_task_impl
  45: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  46: rustc_typeck::check_crate::{{closure}}::{{closure}}
  47: rustc::util::common::time
  48: rustc_typeck::check_crate
  49: rustc_interface::passes::analysis
  50: rustc::ty::query::__query_compute::analysis
  51: rustc::dep_graph::graph::DepGraph::with_task_impl
  52: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  53: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
  54: rustc_interface::passes::create_global_ctxt::{{closure}}
  55: rustc_interface::interface::run_compiler_in_existing_thread_pool
  56: std::thread::local::LocalKey<T>::with
  57: scoped_tls::ScopedKey<T>::set
  58: syntax::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 1.40.0-nightly (702b45e40 2019-10-01) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental --crate-type lib

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

GDB backtrace log using the latest nightly 2019-10-11 during the looooong compile:

GNU gdb (Ubuntu 8.2-0ubuntu1) 8.2
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word".
Attaching to process 14082
[New LWP 14083]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007f70a82d06f5 in __GI___pthread_timedjoin_ex (threadid=140121819051776, thread_return=0x0, abstime=0x0, block=<optimized out>) at pthread_join_common.c:89
89	pthread_join_common.c: Aucun fichier ou dossier de ce type.
warning: Missing auto-load script at offset 0 in section .debug_gdb_scripts
of file /home/simon/git/proj-rs/target/debug/deps/libproc_macro_hack_impl-a27fb5ed26a0da81.so.
Use `info auto-load python-scripts [REGEXP]' to list them.

Thread 2 (Thread 0x7f70a73ff700 (LWP 14083)):
#0  0x00007f70aa07d218 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#1  0x00007f70a9d2c13e in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#2  0x00007f70a9f0683b in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#3  0x00007f70a9f21674 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#4  0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#5  0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#6  0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#7  0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#8  0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#9  0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#10 0x00007f70a9f08448 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#11 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#12 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#13 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#14 0x00007f70a9f2154e in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#15 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#16 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#17 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#18 0x00007f70a9f216a5 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#19 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#20 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#21 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#22 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#23 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#24 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#25 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#26 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#27 0x00007f70a9f08536 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#28 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#29 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#30 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#31 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#32 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#33 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#34 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#35 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#36 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#37 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#38 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#39 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#40 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#41 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#42 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#43 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#44 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#45 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#46 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#47 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#48 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#49 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#50 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#51 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#52 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#53 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#54 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#55 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#56 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#57 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#58 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#59 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#60 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#61 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#62 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#63 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#64 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#65 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#66 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#67 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#68 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#69 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#70 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#71 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#72 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#73 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#74 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#75 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#76 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#77 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#78 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#79 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#80 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#81 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#82 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#83 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#84 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#85 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#86 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#87 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#88 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#89 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#90 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#91 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#92 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#93 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#94 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#95 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#96 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#97 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#98 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#99 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#100 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#101 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#102 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#103 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#104 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#105 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#106 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#107 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#108 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#109 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#110 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#111 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#112 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#113 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#114 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#115 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#116 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#117 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#118 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#119 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#120 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#121 0x00007f70a9d2cafd in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#122 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#123 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#124 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#125 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#126 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#127 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#128 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#129 0x00007f70a9f21421 in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#130 0x00007f70a9c20135 in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type::OpaqueTypeExpander::expand_opaque_ty () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#131 0x00007f70a9c2011c in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type::OpaqueTypeExpander::expand_opaque_ty () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#132 0x00007f70a9d2cade in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#133 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#134 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#135 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#136 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#137 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#138 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#139 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#140 0x00007f70a9c1fec9 in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type::OpaqueTypeExpander::expand_opaque_ty () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#141 0x00007f70a9d2cade in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#142 0x00007f70a9f0997c in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#143 0x00007f70a9f215ba in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#144 0x00007f70a9c97d9a in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#145 0x00007f70a9d22208 in <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#146 0x00007f70a9f08226 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#147 0x00007f70a9f2158c in rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable for &rustc::ty::TyS>::super_fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#148 0x00007f70a9f08423 in rustc::ty::fold::TypeFoldable::fold_with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#149 0x00007f70a9c1fec9 in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type::OpaqueTypeExpander::expand_opaque_ty () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#150 0x00007f70a9c2011c in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type::OpaqueTypeExpander::expand_opaque_ty () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#151 0x00007f70aa2c8089 in rustc::ty::util::<impl rustc::ty::context::TyCtxt>::try_expand_impl_trait_type () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#152 0x00007f70a8e0e295 in rustc_typeck::check::check_item_type () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#153 0x00007f70a8e331b6 in rustc::hir::map::Map::visit_item_likes_in_module () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#154 0x00007f70a8e0b0a4 in rustc_typeck::check::check_mod_item_types () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#155 0x00007f70a90296ba in rustc::ty::query::__query_compute::check_mod_item_types () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#156 0x00007f70a8eef1eb in rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::check_mod_item_types>::compute () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#157 0x00007f70a8e61f57 in rustc::dep_graph::graph::DepGraph::with_task_impl () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#158 0x00007f70a8f574d1 in rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#159 0x00007f70a8eefbb5 in rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::ensure_query () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#160 0x00007f70a8fe9d19 in rustc_typeck::check_crate::{{closure}} () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#161 0x00007f70a8fe28c6 in rustc::util::common::time () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#162 0x00007f70a9010dc4 in rustc_typeck::check_crate () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#163 0x00007f70a89190db in rustc_interface::passes::analysis () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#164 0x00007f70a88b4d31 in rustc::ty::query::__query_compute::analysis () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#165 0x00007f70a88bdc99 in rustc::dep_graph::graph::DepGraph::with_task_impl () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#166 0x00007f70a8849a5f in rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#167 0x00007f70a884647a in rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}} () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#168 0x00007f70a894c11a in rustc_interface::passes::create_global_ctxt::{{closure}} () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#169 0x00007f70a8845b8e in rustc_interface::passes::BoxedGlobalCtxt::enter () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#170 0x00007f70a887d1be in rustc_interface::interface::run_compiler_in_existing_thread_pool () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#171 0x00007f70a8888b42 in std::thread::local::LocalKey<T>::with () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#172 0x00007f70a887951e in scoped_tls::ScopedKey<T>::set () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#173 0x00007f70a88a7192 in syntax::with_globals () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#174 0x00007f70a88ac612 in std::sys_common::backtrace::__rust_begin_short_backtrace () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#175 0x00007f70a83811ba in __rust_maybe_catch_panic () at src/libpanic_unwind/lib.rs:80
No locals.
#176 0x00007f70a88b9849 in core::ops::function::FnOnce::call_once{{vtable-shim}} () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#177 0x00007f70a835223f in <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once () at /rustc/898f36c83cc28d7921a1d7b3605323dc5cfcf533/src/liballoc/boxed.rs:932
No locals.
#178 0x00007f70a837fe60 in <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once () at /rustc/898f36c83cc28d7921a1d7b3605323dc5cfcf533/src/liballoc/boxed.rs:932
No locals.
#179 std::sys_common::thread::start_thread () at src/libstd/sys_common/thread.rs:13
No locals.
#180 std::sys::unix::thread::Thread::new::thread_start () at src/libstd/sys/unix/thread.rs:79
No locals.
#181 0x00007f70a82cf164 in start_thread (arg=<optimized out>) at pthread_create.c:486
        ret = <optimized out>
        pd = <optimized out>
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140121819051776, 2257514283271704495, 140736549587902, 140736549587903, 140736549588160, 140121819042496, -2182834905241104465, -2182806428565647441}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#182 0x00007f70a81e5def in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
No locals.

Thread 1 (Thread 0x7f70a7caa440 (LWP 14082)):
#0  0x00007f70a82d06f5 in __GI___pthread_timedjoin_ex (threadid=140121819051776, thread_return=0x0, abstime=0x0, block=<optimized out>) at pthread_join_common.c:89
        __tid = 14083
        _buffer = {__routine = 0x7f70a82d04f0 <cleanup>, __arg = 0x7f70a73ffd28, __canceltype = 33554432, __prev = 0x0}
        oldtype = 0
        pd = 0x7f70a73ff700
        self = <optimized out>
        result = 0
#1  0x00007f70a837ff1d in std::sys::unix::thread::Thread::join () at src/libstd/sys/unix/thread.rs:179
No locals.
#2  0x00007f70a88b8d03 in std::thread::JoinHandle<T>::join () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#3  0x00007f70a88abfcd in rustc_interface::util::spawn_thread_pool () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#4  0x00007f70a8869b79 in rustc_driver::run_compiler () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#5  0x00007f70a8878414 in <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#6  0x00007f70a88c54cc in std::panicking::try::do_call () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#7  0x00007f70a83811ba in __rust_maybe_catch_panic () at src/libpanic_unwind/lib.rs:80
No locals.
#8  0x00007f70a886f2d9 in rustc_driver::catch_fatal_errors () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#9  0x00007f70a88703f1 in rustc_driver::main () from /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-b4efb057fa528f07.so
No symbol table info available.
#10 0x000055e0901e63e3 in std::rt::lang_start::{{closure}} ()
No symbol table info available.
#11 0x00007f70a8370433 in std::rt::lang_start_internal::{{closure}} () at src/libstd/rt.rs:48
No locals.
#12 std::panicking::try::do_call () at src/libstd/panicking.rs:288
No locals.
#13 0x00007f70a83811ba in __rust_maybe_catch_panic () at src/libpanic_unwind/lib.rs:80
No locals.
#14 0x00007f70a8370fbd in std::panicking::try () at src/libstd/panicking.rs:267
No locals.
#15 std::panic::catch_unwind () at src/libstd/panic.rs:394
No locals.
#16 std::rt::lang_start_internal () at src/libstd/rt.rs:47
No locals.
#17 0x000055e0901e6442 in main ()
No symbol table info available.
A debugging session is active.

	Inferior 1 [process 14082] will be detached.

Quit anyway? (y or n) y
Detaching from program: /home/simon/.rustup/toolchains/nightly-2019-10-11-x86_64-unknown-linux-gnu/bin/rustc, process 14082
[Inferior 1 (process 14082) detached]

[magnet]

I've left it run ... and it turns out it doesn't hang forever

Finished dev [unoptimized + debuginfo] target(s) in 12m 09s

Compared to 1m 07s in beta-2019-10-03

[Mark-Simulacrum]

Can you provide source code in some fashion? I wonder if this might be aided by @tmandry's recent work optimizing rustc_typeck::check::check_item_type -- #65147?

Since the backtrace seems to show us in "try_expand_impl_trait" here as well I'm going to presume that the answer is yes and close as a duplicate; you can probably check locally by using rustup-toolchain-install-master with 0d2ff89f766a2f16a09c41ee7c65453980e81908 as the commit.

[magnet]

That was a good guess! My project also uses async/await heavily. I've tried the commit you mentioned and the performance is even better than before.

Cold cargo check with the toolchain from that 0d2ff89f766a2f16a09c41ee7c65453980e81908:
Finished dev [unoptimized + debuginfo] target(s) in 1m 36s

(compared to 12m last time I tried with a recent nightly).