ICE: Unmarked public member in std::cmp::Reverse

[mzji]

Stack trace:

error: internal compiler error: src\librustc\middle\stability.rs:583: encountered unmarked API
  --> timer.rs:45:36
   |
45 |                 let (until, do_) = later.0;
   |                                    ^^^^^^^

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 1.20.0-nightly (067971139 2017-07-02) running on x86_64-pc-windows-msvc

note: run with `RUST_BACKTRACE=1` for a backtrace

thread 'rustc' panicked at 'Box<Any>', src\librustc_errors\lib.rs:426:8
stack backtrace:
   0: std::net::tcp::TcpListener::incoming
   1: std::panicking::Location::column
   2: std::panicking::Location::column
   3: std::panicking::rust_panic_with_hook
   4: <unknown>
   5: <unknown>
   6: rustc::session::bug_fmt
   7: rustc::session::bug_fmt
   8: rustc::session::bug_fmt
   9: rustc::middle::stability::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::check_stability
  10: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  11: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  12: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  13: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  14: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  15: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  16: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  17: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  18: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  19: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  20: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  21: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  22: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  23: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  24: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  25: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  26: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  27: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  28: <rustc_typeck::check::GatherLocalsVisitor<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_pat
  29: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'v>>::visit_impl_item
  30: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  31: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  32: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  33: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'v>>::visit_impl_item
  34: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  35: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  36: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  37: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'v>>::visit_impl_item
  38: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  39: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  40: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  41: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  42: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  43: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  44: <rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx> as rustc_typeck::astconv::AstConv<'gcx, 'tcx>>::set_tainted_by_errors
  45: <rustc_typeck::check::GatherLocalsVisitor<'a, 'gcx, 'tcx> as rustc::hir::intravisit::Visitor<'gcx>>::visit_pat
  46: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  47: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  48: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  49: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  50: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_tables_of
  51: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  52: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  53: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  54: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_tables_of
  55: <rustc_typeck::check::CheckItemTypesVisitor<'a, 'tcx> as rustc::hir::itemlikevisit::ItemLikeVisitor<'tcx>>::visit_item
  56: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get
  57: rustc::ty::maps::TyCtxtAt::typeck_item_bodies
  58: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies
  59: rustc_typeck::check_crate
  60: rustc_driver::driver::count_nodes
  61: rustc_driver::driver::count_nodes
  62: rustc_driver::driver::compile_input
  63: rustc_driver::run_compiler
  64: <unknown>
  65: _rust_maybe_catch_panic
  66: <rustc_driver::derive_registrar::Finder as rustc::hir::itemlikevisit::ItemLikeVisitor<'v>>::visit_impl_item
  67: std::sys::imp::thread::Thread::new
  68: BaseThreadInitThunk

error: Could not compile `proxyhub`.

To learn more, run the command again with --verbose.

The later here is a Reverse<Later>, and Later is :

struct Later {
    until: std::time::Duration,
    do_: fn(Box<Send>),
    thingie: Box<Send>,
}

.

[kennytm]

Reduced.

#![feature(reverse_cmp_key)]

use std::cmp::Reverse;

fn main() {
    let later = Reverse(0u32);
    let _ = later.0;
}

It is just that the field of Reverse has no stability marker (compare with the source code of std::num::Wrapping). cc #40893 #42745.