ICE on with rustc 1.26.0-nightly (f5631d9ac 2018-03-24) and later

[shisoft]

I got ICE for sometime and also searched in issues but cannot find a relative one.
Sorry for not able to produce the minimal cases to pin down the actual failing case in my code base by simply reverting my code. x

This issue does not exists in nightly-2018-03-21. Error message as follows:

error: internal compiler error: librustc/infer/error_reporting/mod.rs:184: impossible case reached

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
stack backtrace:
error: internal compiler error: librustc/infer/error_reporting/mod.rs:184: impossible case reached

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
stack backtrace:
   0:     0x7fa7c8f7ef4b - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::h88d4b1300e862de6
                               at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7fa7c8f4ca00 - std::sys_common::backtrace::print::ha4b25ea03535b6bc
                               at libstd/sys_common/backtrace.rs:71
                               at libstd/sys_common/backtrace.rs:59
   2:     0x7fa7c8f7242d - std::panicking::default_hook::{{closure}}::h89f6c65d34e612c1
                               at libstd/panicking.rs:207
   3:     0x7fa7c8f72185 - std::panicking::default_hook::h97a3d20007e3cd68
                               at libstd/panicking.rs:223
   4:     0x7fa7c55a80bd - core::ops::function::Fn::call::h21c5f1174484de1a
   5:     0x7fa7c8f72979 - std::panicking::rust_panic_with_hook::h47bfd51197e881f4
                               at libstd/panicking.rs:403
   6:     0x7fa7c3fbf269 - std::panicking::begin_panic::he66ba5a4f20558a9
   7:     0x7fa7c3fd94a1 - rustc_errors::Handler::bug::hd2b47daace8879c7
   8:     0x7fa7c5698abf - rustc::session::opt_span_bug_fmt::{{closure}}::h7a285e675f7ecad3
   9:     0x7fa7c56ace35 - rustc::ty::context::tls::with_opt::{{closure}}::hb0c60bbc299dec38
  10:     0x7fa7c5649643 - <std::thread::local::LocalKey<T>>::try_with::h0a97f593c5dcf1c7
  11:     0x7fa7c5640466 - <std::thread::local::LocalKey<T>>::with::h726e9ee6cbe6f2db
  12:     0x7fa7c545f46d - rustc::ty::context::tls::with::hc95b50ac92e9f143
  13:     0x7fa7c545f9d7 - rustc::ty::context::tls::with_opt::ha16a77063b42a873
  14:     0x7fa7c57da6f4 - rustc::session::opt_span_bug_fmt::h85e42a1462a7acb2
  15:     0x7fa7c57da666 - rustc::session::bug_fmt::h9e6b1e77a7b65211
  16:     0x7fa7c53c7ed3 - rustc::infer::error_reporting::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::msg_span_from_free_region::he2ac2a4633d5dfff
  17:     0x7fa7c52775d7 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_region::hd2f22229a00c57c3
  18:     0x7fa7c56b291e - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  19:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  20:     0x7fa7c5596284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  21:     0x7fa7c56a1969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  22:     0x7fa7c56b277f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  23:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  24:     0x7fa7c559a6ec - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h8377cf69a3c2c1f0
  25:     0x7fa7c569ec69 - rustc::ty::fold::TypeFoldable::fold_with::h2dc9610f10be1f49
  26:     0x7fa7c56b28dd - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  27:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  28:     0x7fa7c5242e56 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once::h3a462fd54cf08b8d
  29:     0x7fa7c5598c13 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h61f2f9442aee3a46
  30:     0x7fa7c57f82b0 - <T as rustc::ty::context::InternIteratorElement<T, R>>::intern_with::hddaaaf54af2f5922
  31:     0x7fa7c5277828 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  32:     0x7fa7c5596284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  33:     0x7fa7c56a1969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  34:     0x7fa7c56b277f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  35:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  36:     0x7fa7c5596284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  37:     0x7fa7c56a1969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  38:     0x7fa7c56b277f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  39:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  40:     0x7fa7c5596284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  41:     0x7fa7c56a1969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  42:     0x7fa7c56b277f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  43:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  44:     0x7fa7c5596284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  45:     0x7fa7c56a1969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  46:     0x7fa7c56b277f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  47:     0x7fa7c5277876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  48:     0x7fa7c52be464 - rustc::infer::anon_types::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::infer_anon_definition_from_instantiation::h4382306e1f859274
  49:     0x7fa7c772a322 - rustc_typeck::check::writeback::WritebackCx::visit_anon_types::hb5eb94c81332802f
  50:     0x7fa7c76c20a7 - rustc_typeck::check::writeback::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_body::h340dbe93fe6a6d61
  51:     0x7fa7c7767726 - rustc::ty::context::tls::enter::ha8ae9527661ca966
  52:     0x7fa7c7739560 - rustc::infer::InferCtxtBuilder::enter::h384a6cfe140c0e55
  53:     0x7fa7c76d8441 - rustc_typeck::check::typeck_tables_of::h045a25f5cc18b4e1
  54:     0x7fa7c517929a - rustc::dep_graph::graph::DepGraph::with_task_impl::h38209dd06e555259
  55:     0x7fa7c5131009 - rustc_errors::Handler::track_diagnostics::hb92a0cb7ed53a4fb
  56:     0x7fa7c5401657 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h4e245e41f290c214
  57:     0x7fa7c54b3d3e - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force::h577074b5c2a71819
  58:     0x7fa7c54b45e2 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get::h663470b06f1a9af4
  59:     0x7fa7c535165a - rustc::ty::maps::TyCtxtAt::typeck_tables_of::hef9e3f61ef0afd39
  60:     0x7fa7c54b3c31 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure::h7a7f7d4e96880ddf
  61:     0x7fa7c782e5bd - rustc::session::Session::track_errors::h16333b127c93c6e4
  62:     0x7fa7c76d7fba - rustc_typeck::check::typeck_item_bodies::hf17344a5285ef991
  63:     0x7fa7c51a438b - rustc::dep_graph::graph::DepGraph::with_task_impl::hd12fc88c46806a2c
  64:     0x7fa7c5122306 - rustc_errors::Handler::track_diagnostics::h816b34bde43fe45f
  65:     0x7fa7c5419377 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h8c005ba7475fc1fb
  66:     0x7fa7c54b2a9c - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force::h97a52420d1392948
  67:     0x7fa7c54b32af - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get::h53db8e36934be5c4
  68:     0x7fa7c5351575 - rustc::ty::maps::TyCtxtAt::typeck_item_bodies::h0ff25c11fabef17e
  69:     0x7fa7c547138e - rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies::he8b170ee0ad4618c
  70:     0x7fa7c78535c2 - rustc_typeck::check_crate::h9abc42612774df7a
  71:     0x7fa7c9386fc2 - <std::thread::local::LocalKey<T>>::with::hff6cfdad62c33763
  72:     0x7fa7c9386886 - <std::thread::local::LocalKey<T>>::with::hf73e2e411d5e1bbd
  73:     0x7fa7c93f95cb - rustc::ty::context::TyCtxt::create_and_enter::h4882ed8ffc6c0dcf
  74:     0x7fa7c92f6166 - rustc_driver::driver::compile_input::h976478050b890adf
  75:     0x7fa7c93adc36 - rustc_driver::run_compiler_impl::h1d61215e89cf59af
  76:     0x7fa7c92f3205 - syntax::with_globals::h5f781b83399af32f
  77:     0x7fa7c932609d - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d7c503aecc53ac6
  78:     0x7fa7c8f8d06e - __rust_maybe_catch_panic
                               at libpanic_unwind/lib.rs:102
  79:     0x7fa7c93340f6 - <F as alloc::boxed::FnBox<A>>::call_box::h5cb8e83b4182087c
  80:     0x7fa7c8f841e7 - std::sys_common::thread::start_thread::hf4cb05e0f65cf12c
                               at /checkout/src/liballoc/boxed.rs:793
                               at libstd/sys_common/thread.rs:24
  81:     0x7fa7c8f52f98 - std::sys::unix::thread::Thread::new::thread_start::h7f0887f31dcc98be
                               at libstd/sys/unix/thread.rs:90
  82:     0x7fa7c32fb7fb - start_thread
  83:     0x7fa7c8c29b5e - clone
  84:                0x0 - <unknown>
   0:     0x7faca05ecf4b - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::h88d4b1300e862de6
                               at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7faca05baa00 - std::sys_common::backtrace::print::ha4b25ea03535b6bc
                               at libstd/sys_common/backtrace.rs:71
                               at libstd/sys_common/backtrace.rs:59
   2:     0x7faca05e042d - std::panicking::default_hook::{{closure}}::h89f6c65d34e612c1
                               at libstd/panicking.rs:207
   3:     0x7faca05e0185 - std::panicking::default_hook::h97a3d20007e3cd68
                               at libstd/panicking.rs:223
   4:     0x7fac9cc160bd - core::ops::function::Fn::call::h21c5f1174484de1a
   5:     0x7faca05e0979 - std::panicking::rust_panic_with_hook::h47bfd51197e881f4
                               at libstd/panicking.rs:403
   6:     0x7fac9b62d269 - std::panicking::begin_panic::he66ba5a4f20558a9
   7:     0x7fac9b6474a1 - rustc_errors::Handler::bug::hd2b47daace8879c7
   8:     0x7fac9cd06abf - rustc::session::opt_span_bug_fmt::{{closure}}::h7a285e675f7ecad3
   9:     0x7fac9cd1ae35 - rustc::ty::context::tls::with_opt::{{closure}}::hb0c60bbc299dec38
  10:     0x7fac9ccb7643 - <std::thread::local::LocalKey<T>>::try_with::h0a97f593c5dcf1c7
  11:     0x7fac9ccae466 - <std::thread::local::LocalKey<T>>::with::h726e9ee6cbe6f2db
  12:     0x7fac9cacd46d - rustc::ty::context::tls::with::hc95b50ac92e9f143
  13:     0x7fac9cacd9d7 - rustc::ty::context::tls::with_opt::ha16a77063b42a873
  14:     0x7fac9ce486f4 - rustc::session::opt_span_bug_fmt::h85e42a1462a7acb2
  15:     0x7fac9ce48666 - rustc::session::bug_fmt::h9e6b1e77a7b65211
  16:     0x7fac9ca35ed3 - rustc::infer::error_reporting::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::msg_span_from_free_region::he2ac2a4633d5dfff
  17:     0x7fac9c8e55d7 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_region::hd2f22229a00c57c3
  18:     0x7fac9cd2091e - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  19:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  20:     0x7fac9cc04284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  21:     0x7fac9cd0f969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  22:     0x7fac9cd2077f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  23:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  24:     0x7fac9cc086ec - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h8377cf69a3c2c1f0
  25:     0x7fac9cd0cc69 - rustc::ty::fold::TypeFoldable::fold_with::h2dc9610f10be1f49
  26:     0x7fac9cd208dd - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  27:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  28:     0x7fac9c8b0e56 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once::h3a462fd54cf08b8d
  29:     0x7fac9cc06c13 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h61f2f9442aee3a46
  30:     0x7fac9ce662b0 - <T as rustc::ty::context::InternIteratorElement<T, R>>::intern_with::hddaaaf54af2f5922
  31:     0x7fac9c8e5828 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  32:     0x7fac9cc04284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  33:     0x7fac9cd0f969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  34:     0x7fac9cd2077f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  35:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  36:     0x7fac9cc04284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  37:     0x7fac9cd0f969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  38:     0x7fac9cd2077f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  39:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  40:     0x7fac9cc04284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  41:     0x7fac9cd0f969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  42:     0x7fac9cd2077f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  43:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  44:     0x7fac9cc04284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  45:     0x7fac9cd0f969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  46:     0x7fac9cd2077f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  47:     0x7fac9c8e5876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  48:     0x7fac9c92c464 - rustc::infer::anon_types::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::infer_anon_definition_from_instantiation::h4382306e1f859274
  49:     0x7fac9ed98322 - rustc_typeck::check::writeback::WritebackCx::visit_anon_types::hb5eb94c81332802f
  50:     0x7fac9ed300a7 - rustc_typeck::check::writeback::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_body::h340dbe93fe6a6d61
  51:     0x7fac9edd5726 - rustc::ty::context::tls::enter::ha8ae9527661ca966
  52:     0x7fac9eda7560 - rustc::infer::InferCtxtBuilder::enter::h384a6cfe140c0e55
  53:     0x7fac9ed46441 - rustc_typeck::check::typeck_tables_of::h045a25f5cc18b4e1
  54:     0x7fac9c7e729a - rustc::dep_graph::graph::DepGraph::with_task_impl::h38209dd06e555259
  55:     0x7fac9c79f009 - rustc_errors::Handler::track_diagnostics::hb92a0cb7ed53a4fb
  56:     0x7fac9ca6f657 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h4e245e41f290c214
  57:     0x7fac9cb21d3e - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force::h577074b5c2a71819
  58:     0x7fac9cb225e2 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get::h663470b06f1a9af4
  59:     0x7fac9c9bf65a - rustc::ty::maps::TyCtxtAt::typeck_tables_of::hef9e3f61ef0afd39
  60:     0x7fac9cb21c31 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure::h7a7f7d4e96880ddf
  61:     0x7fac9ee9c5bd - rustc::session::Session::track_errors::h16333b127c93c6e4
  62:     0x7fac9ed45fba - rustc_typeck::check::typeck_item_bodies::hf17344a5285ef991
  63:     0x7fac9c81238b - rustc::dep_graph::graph::DepGraph::with_task_impl::hd12fc88c46806a2c
  64:     0x7fac9c790306 - rustc_errors::Handler::track_diagnostics::h816b34bde43fe45f
  65:     0x7fac9ca87377 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h8c005ba7475fc1fb
  66:     0x7fac9cb20a9c - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force::h97a52420d1392948
  67:     0x7fac9cb212af - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get::h53db8e36934be5c4
  68:     0x7fac9c9bf575 - rustc::ty::maps::TyCtxtAt::typeck_item_bodies::h0ff25c11fabef17e
  69:     0x7fac9cadf38e - rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies::he8b170ee0ad4618c
  70:     0x7fac9eec15c2 - rustc_typeck::check_crate::h9abc42612774df7a
  71:     0x7faca09f4fc2 - <std::thread::local::LocalKey<T>>::with::hff6cfdad62c33763
  72:     0x7faca09f4886 - <std::thread::local::LocalKey<T>>::with::hf73e2e411d5e1bbd
  73:     0x7faca0a675cb - rustc::ty::context::TyCtxt::create_and_enter::h4882ed8ffc6c0dcf
  74:     0x7faca0964166 - rustc_driver::driver::compile_input::h976478050b890adf
  75:     0x7faca0a1bc36 - rustc_driver::run_compiler_impl::h1d61215e89cf59af
  76:     0x7faca0961205 - syntax::with_globals::h5f781b83399af32f
  77:     0x7faca099409d - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d7c503aecc53ac6
  78:     0x7faca05fb06e - __rust_maybe_catch_panic
                               at libpanic_unwind/lib.rs:102
  79:     0x7faca09a20f6 - <F as alloc::boxed::FnBox<A>>::call_box::h5cb8e83b4182087c
  80:     0x7faca05f21e7 - std::sys_common::thread::start_thread::hf4cb05e0f65cf12c
                               at /checkout/src/liballoc/boxed.rs:793
                               at libstd/sys_common/thread.rs:24
  81:     0x7faca05c0f98 - std::sys::unix::thread::Thread::new::thread_start::h7f0887f31dcc98be
                               at libstd/sys/unix/thread.rs:90
  82:     0x7fac9a9697fb - start_thread
  83:     0x7faca0297b5e - clone
  84:                0x0 - <unknown>

meta for 2018-03-21

rustc 1.26.0-nightly (75af15ee6 2018-03-20)
binary: rustc
commit-hash: 75af15ee6ca0c12b699a17984b033363cd25e9c3
commit-date: 2018-03-20
host: x86_64-unknown-linux-gnu
release: 1.26.0-nightly
LLVM version: 6.0

meta for 2018-03-24

rustc 1.26.0-nightly (c08480fce 2018-03-23)
binary: rustc
commit-hash: c08480fce0f39f5c9c6db6dde0dccb375ca0ab14
commit-date: 2018-03-23
host: x86_64-unknown-linux-gnu
release: 1.26.0-nightly
LLVM version: 6.0

I appreciate any hints and suggestions on helping me to reproduce this issue into minimal case but right now I just can't find out what changes in my code caused this problem. My code base is https://github.com/ShisoftResearch/Hivemind/tree/kylo

[shisoft]

I have dig into this and found the snippet of code caused this problem: https://github.com/ShisoftResearch/Hivemind/blob/6618ae71c74ebb21f834c68b661b5fca898f8804/src/context/mod.rs#L53

It should produce an error which did not appeared in previous build

error[E0283]: type annotations required: cannot resolve `_: serde::Serialize`
  --> src/context/mod.rs:54:13
   |
54 |             DataSet::from_block_storage(
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
note: required by `<resource::DataSet<T>>::from_block_storage`
  --> src/resource/mod.rs:63:5
   |
63 | /     pub fn from_block_storage(
64 | |         manager: &Arc<BlockManager>,
65 | |         server_id: u64,
66 | |         task: UUID,
...  |
75 | |             }))
76 | |     }
   | |_____^

This is not the whole story, when I assign DataSet::from_block_storage to a variable and return the variable, it got the same ICE but the type inference error gone.

I finally able to mitigate the problem by turning the return type from impl Future to Box<Future<?, ?>>

[sinkuu]

I got a possibly same ICE with this code: https://gist.github.com/sinkuu/7d9e6dcf6397546866f367b281562c30

Meta:

rustc 1.27.0-nightly (fb44b4c0e 2018-04-04)
binary: rustc
commit-hash: fb44b4c0eb1d344f84f7bb2c90f28e31a8a180be
commit-date: 2018-04-04
host: x86_64-unknown-linux-gnu
release: 1.27.0-nightly
LLVM version: 6.0

Backtrace:

error: internal compiler error: librustc/infer/error_reporting/mod.rs:184: impossible case reached

thread 'main' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::print
             at libstd/sys_common/backtrace.rs:71
             at libstd/sys_common/backtrace.rs:59
   2: std::panicking::default_hook::{{closure}}
             at libstd/panicking.rs:207
   3: std::panicking::default_hook
             at libstd/panicking.rs:223
   4: core::ops::function::Fn::call
   5: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:403
   6: std::panicking::begin_panic
   7: rustc_errors::Handler::bug
   8: rustc::session::opt_span_bug_fmt::{{closure}}
   9: rustc::ty::context::tls::with_opt::{{closure}}
  10: <std::thread::local::LocalKey<T>>::try_with
  11: <std::thread::local::LocalKey<T>>::with
  12: rustc::ty::context::tls::with
  13: rustc::ty::context::tls::with_opt
  14: rustc::session::opt_span_bug_fmt
  15: rustc::session::bug_fmt
  16: rustc::infer::error_reporting::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::msg_span_from_free_region
  17: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_region
  18: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  19: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  20: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  21: rustc::ty::fold::TypeFoldable::fold_with
  22: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  23: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  24: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  25: rustc::ty::fold::TypeFoldable::fold_with
  26: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  27: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  28: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once
  29: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  30: <T as rustc::ty::context::InternIteratorElement<T, R>>::intern_with
  31: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  32: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  33: rustc::ty::fold::TypeFoldable::fold_with
  34: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  35: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  36: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  37: rustc::ty::fold::TypeFoldable::fold_with
  38: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  39: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  40: <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter
  41: rustc::ty::fold::TypeFoldable::fold_with
  42: rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with
  43: <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty
  44: rustc::infer::anon_types::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::infer_anon_definition_from_instantiation
  45: rustc_typeck::check::writeback::WritebackCx::visit_anon_types
  46: rustc_typeck::check::writeback::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_body
  47: rustc::ty::context::tls::enter
  48: rustc::infer::InferCtxtBuilder::enter
  49: rustc_typeck::check::typeck_tables_of
  50: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::compute_result
  51: rustc::dep_graph::graph::DepGraph::with_task_impl
  52: rustc_errors::Handler::track_diagnostics
  53: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  54: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force
  55: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get
  56: rustc::ty::maps::TyCtxtAt::typeck_tables_of
  57: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure
  58: rustc::session::Session::track_errors
  59: rustc_typeck::check::typeck_item_bodies
  60: rustc::dep_graph::graph::DepGraph::with_task_impl
  61: rustc_errors::Handler::track_diagnostics
  62: rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check
  63: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force
  64: rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get
  65: rustc::ty::maps::TyCtxtAt::typeck_item_bodies
  66: rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies
  67: rustc_typeck::check_crate
  68: <std::thread::local::LocalKey<T>>::with
  69: <std::thread::local::LocalKey<T>>::with
  70: rustc::ty::context::TyCtxt::create_and_enter
  71: rustc_driver::driver::compile_input
  72: rustc_driver::run_compiler_impl
  73: syntax::with_globals
  74: rustc_driver::run
  75: rustc_driver::main
  76: std::rt::lang_start::{{closure}}
  77: std::panicking::try::do_call
             at libstd/rt.rs:59
             at libstd/panicking.rs:306
  78: __rust_maybe_catch_panic
             at libpanic_unwind/lib.rs:102
  79: std::rt::lang_start_internal
             at libstd/panicking.rs:285
             at libstd/panic.rs:361
             at libstd/rt.rs:58
  80: main
  81: __libc_start_main
  82: <unknown>

[mchesser]

This gives me the same ICE:

fn iter<'a>(data: &'a [usize]) -> impl Iterator<Item = usize> + 'a {
    data.iter().map(|x| x).map(|x| *x)
}

However this does not ICE:

fn iter<'a>(data: &'a [usize]) -> impl Iterator<Item = usize> + 'a {
    data.iter().map(|x| *x).map(|x| x)
}

[sinkuu]

data.iter().map(|x| x).map(|x| *x)

The closure in .map(|x| x) is (&'a u32) -> &'(ReScope) u32, therefore tcx.note_and_explain_free_region causes ICE.

data.iter().map(|x| *x).map(|x| x)

(&'a u32) -> u32 and (u32) -> u32, so all is fine.

[shisoft]

Hi all. #49730 does not fix my issue.

error: internal compiler error: librustc/infer/error_reporting/mod.rs:184: impossible case reached

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
stack backtrace:
error: internal compiler error: librustc/infer/error_reporting/mod.rs:184: impossible case reached

thread 'rustc' panicked at 'Box<Any>', librustc_errors/lib.rs:543:9
stack backtrace:
   0:     0x7f6793e60f4b - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::h88d4b1300e862de6
                               at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7f6793e2ea00 - std::sys_common::backtrace::print::ha4b25ea03535b6bc
                               at libstd/sys_common/backtrace.rs:71
                               at libstd/sys_common/backtrace.rs:59
   2:     0x7f6793e5442d - std::panicking::default_hook::{{closure}}::h89f6c65d34e612c1
                               at libstd/panicking.rs:207
   3:     0x7f6793e54185 - std::panicking::default_hook::h97a3d20007e3cd68
                               at libstd/panicking.rs:223
   4:     0x7f679048a0bd - core::ops::function::Fn::call::h21c5f1174484de1a
   5:     0x7f6793e54979 - std::panicking::rust_panic_with_hook::h47bfd51197e881f4
                               at libstd/panicking.rs:403
   6:     0x7f678eea1269 - std::panicking::begin_panic::he66ba5a4f20558a9
   7:     0x7f678eebb4a1 - rustc_errors::Handler::bug::hd2b47daace8879c7
   8:     0x7f679057aabf - rustc::session::opt_span_bug_fmt::{{closure}}::h7a285e675f7ecad3
   9:     0x7f679058ee35 - rustc::ty::context::tls::with_opt::{{closure}}::hb0c60bbc299dec38
  10:     0x7f679052b643 - <std::thread::local::LocalKey<T>>::try_with::h0a97f593c5dcf1c7
  11:     0x7f6790522466 - <std::thread::local::LocalKey<T>>::with::h726e9ee6cbe6f2db
  12:     0x7f679034146d - rustc::ty::context::tls::with::hc95b50ac92e9f143
  13:     0x7f67903419d7 - rustc::ty::context::tls::with_opt::ha16a77063b42a873
  14:     0x7f67906bc6f4 - rustc::session::opt_span_bug_fmt::h85e42a1462a7acb2
  15:     0x7f67906bc666 - rustc::session::bug_fmt::h9e6b1e77a7b65211
  16:     0x7f67902a9ed3 - rustc::infer::error_reporting::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::msg_span_from_free_region::he2ac2a4633d5dfff
  17:     0x7f67901595d7 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_region::hd2f22229a00c57c3
  18:     0x7f679059491e - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  19:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  20:     0x7f6790478284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  21:     0x7f6790583969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  22:     0x7f679059477f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  23:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  24:     0x7f679047c6ec - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h8377cf69a3c2c1f0
  25:     0x7f6790580c69 - rustc::ty::fold::TypeFoldable::fold_with::h2dc9610f10be1f49
  26:     0x7f67905948dd - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  27:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  28:     0x7f6790124e56 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once::h3a462fd54cf08b8d
  29:     0x7f679047ac13 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h61f2f9442aee3a46
  30:     0x7f67906da2b0 - <T as rustc::ty::context::InternIteratorElement<T, R>>::intern_with::hddaaaf54af2f5922
  31:     0x7f6790159828 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  32:     0x7f6790478284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  33:     0x7f6790583969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  34:     0x7f679059477f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  35:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  36:     0x7f6790478284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  37:     0x7f6790583969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  38:     0x7f679059477f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  39:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  40:     0x7f6790478284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  41:     0x7f6790583969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  42:     0x7f679059477f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  43:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  44:     0x7f6790478284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  45:     0x7f6790583969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  46:     0x7f679059477f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  47:     0x7f6790159876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  48:     0x7f67901a0464 - rustc::infer::anon_types::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::infer_anon_definition_from_instantiation::h4382306e1f859274
  49:     0x7f679260c322 - rustc_typeck::check::writeback::WritebackCx::visit_anon_types::hb5eb94c81332802f
  50:     0x7f67925a40a7 - rustc_typeck::check::writeback::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_body::h340dbe93fe6a6d61
  51:     0x7f6792649726 - rustc::ty::context::tls::enter::ha8ae9527661ca966
  52:     0x7f679261b560 - rustc::infer::InferCtxtBuilder::enter::h384a6cfe140c0e55
  53:     0x7f67925ba441 - rustc_typeck::check::typeck_tables_of::h045a25f5cc18b4e1
  54:     0x7f679005b29a - rustc::dep_graph::graph::DepGraph::with_task_impl::h38209dd06e555259
  55:     0x7f6790013009 - rustc_errors::Handler::track_diagnostics::hb92a0cb7ed53a4fb
  56:     0x7f67902e3657 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h4e245e41f290c214
  57:     0x7f6790395d3e - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force::h577074b5c2a71819
  58:     0x7f67903965e2 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get::h663470b06f1a9af4
  59:     0x7f679023365a - rustc::ty::maps::TyCtxtAt::typeck_tables_of::hef9e3f61ef0afd39
  60:     0x7f6790395c31 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure::h7a7f7d4e96880ddf
  61:     0x7f67927105bd - rustc::session::Session::track_errors::h16333b127c93c6e4
  62:     0x7f67925b9fba - rustc_typeck::check::typeck_item_bodies::hf17344a5285ef991
  63:     0x7f679008638b - rustc::dep_graph::graph::DepGraph::with_task_impl::hd12fc88c46806a2c
  64:     0x7f6790004306 - rustc_errors::Handler::track_diagnostics::h816b34bde43fe45f
  65:     0x7f67902fb377 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h8c005ba7475fc1fb
  66:     0x7f6790394a9c - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force::h97a52420d1392948
  67:     0x7f67903952af - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get::h53db8e36934be5c4
  68:     0x7f6790233575 - rustc::ty::maps::TyCtxtAt::typeck_item_bodies::h0ff25c11fabef17e
  69:     0x7f679035338e - rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies::he8b170ee0ad4618c
  70:     0x7f67927355c2 - rustc_typeck::check_crate::h9abc42612774df7a
  71:     0x7f6794268fc2 - <std::thread::local::LocalKey<T>>::with::hff6cfdad62c33763
  72:     0x7f6794268886 - <std::thread::local::LocalKey<T>>::with::hf73e2e411d5e1bbd
  73:     0x7f67942db5cb - rustc::ty::context::TyCtxt::create_and_enter::h4882ed8ffc6c0dcf
  74:     0x7f67941d8166 - rustc_driver::driver::compile_input::h976478050b890adf
  75:     0x7f679428fc36 - rustc_driver::run_compiler_impl::h1d61215e89cf59af
  76:     0x7f67941d5205 - syntax::with_globals::h5f781b83399af32f
  77:     0x7f679420809d - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d7c503aecc53ac6
  78:     0x7f6793e6f06e - __rust_maybe_catch_panic
                               at libpanic_unwind/lib.rs:102
  79:     0x7f67942160f6 - <F as alloc::boxed::FnBox<A>>::call_box::h5cb8e83b4182087c
  80:     0x7f6793e661e7 - std::sys_common::thread::start_thread::hf4cb05e0f65cf12c
                               at /checkout/src/liballoc/boxed.rs:793
                               at libstd/sys_common/thread.rs:24
  81:     0x7f6793e34f98 - std::sys::unix::thread::Thread::new::thread_start::h7f0887f31dcc98be
                               at libstd/sys/unix/thread.rs:90
  82:     0x7f678e1dd7fb - start_thread
  83:     0x7f6793b0bb5e - clone
  84:                0x0 - <unknown>
   0:     0x7f6f458c5f4b - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::h88d4b1300e862de6
                               at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1:     0x7f6f45893a00 - std::sys_common::backtrace::print::ha4b25ea03535b6bc
                               at libstd/sys_common/backtrace.rs:71
                               at libstd/sys_common/backtrace.rs:59
   2:     0x7f6f458b942d - std::panicking::default_hook::{{closure}}::h89f6c65d34e612c1
                               at libstd/panicking.rs:207
   3:     0x7f6f458b9185 - std::panicking::default_hook::h97a3d20007e3cd68
                               at libstd/panicking.rs:223
   4:     0x7f6f41eef0bd - core::ops::function::Fn::call::h21c5f1174484de1a
   5:     0x7f6f458b9979 - std::panicking::rust_panic_with_hook::h47bfd51197e881f4
                               at libstd/panicking.rs:403
   6:     0x7f6f40906269 - std::panicking::begin_panic::he66ba5a4f20558a9
   7:     0x7f6f409204a1 - rustc_errors::Handler::bug::hd2b47daace8879c7
   8:     0x7f6f41fdfabf - rustc::session::opt_span_bug_fmt::{{closure}}::h7a285e675f7ecad3
   9:     0x7f6f41ff3e35 - rustc::ty::context::tls::with_opt::{{closure}}::hb0c60bbc299dec38
  10:     0x7f6f41f90643 - <std::thread::local::LocalKey<T>>::try_with::h0a97f593c5dcf1c7
  11:     0x7f6f41f87466 - <std::thread::local::LocalKey<T>>::with::h726e9ee6cbe6f2db
  12:     0x7f6f41da646d - rustc::ty::context::tls::with::hc95b50ac92e9f143
  13:     0x7f6f41da69d7 - rustc::ty::context::tls::with_opt::ha16a77063b42a873
  14:     0x7f6f421216f4 - rustc::session::opt_span_bug_fmt::h85e42a1462a7acb2
  15:     0x7f6f42121666 - rustc::session::bug_fmt::h9e6b1e77a7b65211
  16:     0x7f6f41d0eed3 - rustc::infer::error_reporting::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::msg_span_from_free_region::he2ac2a4633d5dfff
  17:     0x7f6f41bbe5d7 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_region::hd2f22229a00c57c3
  18:     0x7f6f41ff991e - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  19:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  20:     0x7f6f41edd284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  21:     0x7f6f41fe8969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  22:     0x7f6f41ff977f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  23:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  24:     0x7f6f41ee16ec - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h8377cf69a3c2c1f0
  25:     0x7f6f41fe5c69 - rustc::ty::fold::TypeFoldable::fold_with::h2dc9610f10be1f49
  26:     0x7f6f41ff98dd - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  27:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  28:     0x7f6f41b89e56 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once::h3a462fd54cf08b8d
  29:     0x7f6f41edfc13 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h61f2f9442aee3a46
  30:     0x7f6f4213f2b0 - <T as rustc::ty::context::InternIteratorElement<T, R>>::intern_with::hddaaaf54af2f5922
  31:     0x7f6f41bbe828 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  32:     0x7f6f41edd284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  33:     0x7f6f41fe8969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  34:     0x7f6f41ff977f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  35:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  36:     0x7f6f41edd284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  37:     0x7f6f41fe8969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  38:     0x7f6f41ff977f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  39:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  40:     0x7f6f41edd284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  41:     0x7f6f41fe8969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  42:     0x7f6f41ff977f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  43:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  44:     0x7f6f41edd284 - <rustc_data_structures::accumulate_vec::AccumulateVec<A> as core::iter::traits::FromIterator<<A as rustc_data_structures::array_vec::Array>::Element>>::from_iter::h123b1b0451a30840
  45:     0x7f6f41fe8969 - rustc::ty::fold::TypeFoldable::fold_with::hadc69145d18b9346
  46:     0x7f6f41ff977f - rustc::ty::structural_impls::<impl rustc::ty::fold::TypeFoldable<'tcx> for &'tcx rustc::ty::TyS<'tcx>>::super_fold_with::hef9c449b0c4daaae
  47:     0x7f6f41bbe876 - <rustc::infer::anon_types::ReverseMapper<'cx, 'gcx, 'tcx> as rustc::ty::fold::TypeFolder<'gcx, 'tcx>>::fold_ty::h5c8b9267b7259e21
  48:     0x7f6f41c05464 - rustc::infer::anon_types::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::infer_anon_definition_from_instantiation::h4382306e1f859274
  49:     0x7f6f44071322 - rustc_typeck::check::writeback::WritebackCx::visit_anon_types::hb5eb94c81332802f
  50:     0x7f6f440090a7 - rustc_typeck::check::writeback::<impl rustc_typeck::check::FnCtxt<'a, 'gcx, 'tcx>>::resolve_type_vars_in_body::h340dbe93fe6a6d61
  51:     0x7f6f440ae726 - rustc::ty::context::tls::enter::ha8ae9527661ca966
  52:     0x7f6f44080560 - rustc::infer::InferCtxtBuilder::enter::h384a6cfe140c0e55
  53:     0x7f6f4401f441 - rustc_typeck::check::typeck_tables_of::h045a25f5cc18b4e1
  54:     0x7f6f41ac029a - rustc::dep_graph::graph::DepGraph::with_task_impl::h38209dd06e555259
  55:     0x7f6f41a78009 - rustc_errors::Handler::track_diagnostics::hb92a0cb7ed53a4fb
  56:     0x7f6f41d48657 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h4e245e41f290c214
  57:     0x7f6f41dfad3e - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::force::h577074b5c2a71819
  58:     0x7f6f41dfb5e2 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::try_get::h663470b06f1a9af4
  59:     0x7f6f41c9865a - rustc::ty::maps::TyCtxtAt::typeck_tables_of::hef9e3f61ef0afd39
  60:     0x7f6f41dfac31 - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_tables_of<'tcx>>::ensure::h7a7f7d4e96880ddf
  61:     0x7f6f441755bd - rustc::session::Session::track_errors::h16333b127c93c6e4
  62:     0x7f6f4401efba - rustc_typeck::check::typeck_item_bodies::hf17344a5285ef991
  63:     0x7f6f41aeb38b - rustc::dep_graph::graph::DepGraph::with_task_impl::hd12fc88c46806a2c
  64:     0x7f6f41a69306 - rustc_errors::Handler::track_diagnostics::h816b34bde43fe45f
  65:     0x7f6f41d60377 - rustc::ty::maps::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::cycle_check::h8c005ba7475fc1fb
  66:     0x7f6f41df9a9c - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::force::h97a52420d1392948
  67:     0x7f6f41dfa2af - rustc::ty::maps::<impl rustc::ty::maps::queries::typeck_item_bodies<'tcx>>::try_get::h53db8e36934be5c4
  68:     0x7f6f41c98575 - rustc::ty::maps::TyCtxtAt::typeck_item_bodies::h0ff25c11fabef17e
  69:     0x7f6f41db838e - rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::typeck_item_bodies::he8b170ee0ad4618c
  70:     0x7f6f4419a5c2 - rustc_typeck::check_crate::h9abc42612774df7a
  71:     0x7f6f45ccdfc2 - <std::thread::local::LocalKey<T>>::with::hff6cfdad62c33763
  72:     0x7f6f45ccd886 - <std::thread::local::LocalKey<T>>::with::hf73e2e411d5e1bbd
  73:     0x7f6f45d405cb - rustc::ty::context::TyCtxt::create_and_enter::h4882ed8ffc6c0dcf
  74:     0x7f6f45c3d166 - rustc_driver::driver::compile_input::h976478050b890adf
  75:     0x7f6f45cf4c36 - rustc_driver::run_compiler_impl::h1d61215e89cf59af
  76:     0x7f6f45c3a205 - syntax::with_globals::h5f781b83399af32f
  77:     0x7f6f45c6d09d - std::sys_common::backtrace::__rust_begin_short_backtrace::h3d7c503aecc53ac6
  78:     0x7f6f458d406e - __rust_maybe_catch_panic
                               at libpanic_unwind/lib.rs:102
  79:     0x7f6f45c7b0f6 - <F as alloc::boxed::FnBox<A>>::call_box::h5cb8e83b4182087c
  80:     0x7f6f458cb1e7 - std::sys_common::thread::start_thread::hf4cb05e0f65cf12c
                               at /checkout/src/liballoc/boxed.rs:793
                               at libstd/sys_common/thread.rs:24
  81:     0x7f6f45899f98 - std::sys::unix::thread::Thread::new::thread_start::h7f0887f31dcc98be
                               at libstd/sys/unix/thread.rs:90
  82:     0x7f6f3fc427fb - start_thread
  83:     0x7f6f45570b5e - clone
  84:                0x0 - <unknown>

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 1.26.0-nightly (c08480fce 2018-03-23) 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

error: Could not compile `hivemind`.
warning: build failed, waiting for other jobs to finish...

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 1.26.0-nightly (c08480fce 2018-03-23) running on x86_64-unknown-linux-gnu

note: compiler flags: -C debuginfo=2 -C incremental

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

[sinkuu]

@shisoft Sorry, I forgot to test with your case. Though you seem to be using a nightly-2018-03-23 which can never contain unmerged #49730, right? https://github.com/ShisoftResearch/Hivemind/tree/kylo depends on proc-macro2-1.1 which is not even compilable with recent nightlies.

[shisoft]

Hi, sorry for the slow reply. I will try that again once the branch have been merged. Any ETA on when it will go into nightly? Thanks

[sinkuu]

Any ETA on when it will go into nightly?

No, it varies due to approval of other PRs. Here is the current queue: https://buildbot2.rust-lang.org/homu/queue/rust

[sinkuu]

Nightly 2018-04-14 contains #49730. Could you reopen if the problem persists?

[pentlander]

As at least one data point, I had the same issue and it was resolved with 2018-04-15.