ICE: assertion failed: self.is_free_or_static(r_a) && self.is_free_or_static(r_b), glacier fixed/74761.rs with --emit=mir -Zsave-analysis #87218

thread 'rustc' panicked at 'assertion failed: self.is_free_or_static(r_a) && self.is_free_or_static(r_b)', compiler/rustc_infer/src/infer/free_regions.rs:77:9
stack backtrace:
   0:     0x7fafad903f00 - std::backtrace_rs::backtrace::libunwind::trace::h0f5cd2ee8b0d7274
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/../../backtrace/src/backtrace/libunwind.rs:90:5
   1:     0x7fafad903f00 - std::backtrace_rs::backtrace::trace_unsynchronized::h06905b5aeda069a1
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fafad903f00 - std::sys_common::backtrace::_print_fmt::h4fe4c7c875072f30
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys_common/backtrace.rs:67:5
   3:     0x7fafad903f00 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hcc0746f004a9b7ef
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys_common/backtrace.rs:46:22
   4:     0x7fafad971cec - core::fmt::write::h9a6d9c74526a6c1b
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/core/src/fmt/mod.rs:1115:17
   5:     0x7fafad8f5655 - std::io::Write::write_fmt::h23dab4cc9ce72ee2
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/io/mod.rs:1663:15
   6:     0x7fafad907c1b - std::sys_common::backtrace::_print::h173dc702502d65d2
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys_common/backtrace.rs:49:5
   7:     0x7fafad907c1b - std::sys_common::backtrace::print::h61bd27c4742ba817
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys_common/backtrace.rs:36:9
   8:     0x7fafad907c1b - std::panicking::default_hook::{{closure}}::hcaae87f0495ae613
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/panicking.rs:208:50
   9:     0x7fafad9076f1 - std::panicking::default_hook::h0538e728ee080db0
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/panicking.rs:225:9
  10:     0x7fafae0de1c1 - rustc_driver::DEFAULT_HOOK::{{closure}}::{{closure}}::h432ae30fc20e6372
  11:     0x7fafad908449 - std::panicking::rust_panic_with_hook::h3039e236b6ca482c
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/panicking.rs:626:17
  12:     0x7fafad907ed7 - std::panicking::begin_panic_handler::{{closure}}::h884fbab544ffd91c
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/panicking.rs:517:13
  13:     0x7fafad9043fc - std::sys_common::backtrace::__rust_end_short_backtrace::hdaf2e18ba3d91210
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys_common/backtrace.rs:141:18
  14:     0x7fafad907e69 - rust_begin_unwind
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/panicking.rs:515:5
  15:     0x7fafad8d2e71 - core::panicking::panic_fmt::hcf5f6d96e1dd7099
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/core/src/panicking.rs:92:14
  16:     0x7fafad8d2dbd - core::panicking::panic::hd695e3b1d0dd4ef4
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/core/src/panicking.rs:50:5
  17:     0x7fafaef09abd - <rustc_infer::infer::free_regions::FreeRegionMap as rustc_infer::infer::free_regions::FreeRegionRelations>::sub_free_regions::hdfae93b7960847d5
  18:     0x7fafaf37719f - <rustc_infer::infer::InferCtxt as rustc_trait_selection::opaque_types::InferCtxtExt>::constrain_opaque_types::h1b8e03fe94050281
  19:     0x7fafaf3362fd - rustc_typeck::check::regionck::RegionCtxt::visit_fn_body::h2d0701b7799ad1f8
  20:     0x7fafaf2ea77f - rustc_typeck::check::regionck::<impl rustc_typeck::check::fn_ctxt::FnCtxt>::regionck_fn::he03fdfa01ae16140
  21:     0x7fafaf36a9a0 - rustc_infer::infer::InferCtxtBuilder::enter::h5b0049019ece2d91
  22:     0x7fafaf3c3499 - rustc_typeck::check::typeck::h45b639d5069c89f7
  23:     0x7fafaf4c5a0c - rustc_query_system::query::plumbing::get_query_impl::h292344179c2f1a96
  24:     0x7fafaf5332db - <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::typeck::h9b8dd6db5e7e34f0
  25:     0x7fafae12ee19 - rustc_save_analysis::dump_visitor::DumpVisitor::process_method::hc8aa5dbea4311631
  26:     0x7fafae131806 - rustc_save_analysis::dump_visitor::DumpVisitor::process_impl_item::h59b684c892943cde
  27:     0x7fafae12d2f3 - rustc_save_analysis::dump_visitor::DumpVisitor::nest_typeck_results::h253be14039dac37b
  28:     0x7fafae1344ac - <rustc_save_analysis::dump_visitor::DumpVisitor as rustc_hir::intravisit::Visitor>::visit_item::h9b52cebc0df4f7b9
  29:     0x7fafae12c2b6 - rustc_hir::intravisit::Visitor::visit_nested_item::h9e975cc0f2a00c21
  30:     0x7fafae119c51 - rustc_hir::intravisit::walk_crate::he7f189f23867b6fd
  31:     0x7fafae131c10 - rustc_save_analysis::dump_visitor::DumpVisitor::process_crate::h8b9b619ce8c21fa3
  32:     0x7fafae105b75 - rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps::hd0ffb7bb05686286
  33:     0x7fafae11046b - std::thread::local::LocalKey<T>::with::h614f74b0ec87e973
  34:     0x7fafae0e00b7 - rustc_save_analysis::process_crate::hc449d2bdb96b795f
  35:     0x7fafae0ea7e7 - rustc_session::utils::<impl rustc_session::session::Session>::time::hd147f92cb70cf437
  36:     0x7fafafbe2869 - rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter::hd3df2f2fd8ee2f9c
  37:     0x7fafafbd0ecc - rustc_span::with_source_map::h4320e6c7562b1c81
  38:     0x7fafafbe332a - rustc_interface::interface::create_compiler_and_run::h8b004a10f044574a
  39:     0x7fafafbd6219 - scoped_tls::ScopedKey<T>::set::hc495f050953f2646
  40:     0x7fafafbd2fdb - std::sys_common::backtrace::__rust_begin_short_backtrace::hf6d64874d4b63366
  41:     0x7fafafbd1865 - core::ops::function::FnOnce::call_once{{vtable.shim}}::h44f63dc93d63fbac
  42:     0x7fafad9149f7 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd5b860c6542b008a
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/alloc/src/boxed.rs:1572:9
  43:     0x7fafad9149f7 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hc87b98c8a3a585ed
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/alloc/src/boxed.rs:1572:9
  44:     0x7fafad9149f7 - std::sys::unix::thread::Thread::new::thread_start::ha990175c8f3779cc
                               at /rustc/74ef0c3e404cc72c08b2d1e14506f90d9e877269/library/std/src/sys/unix/thread.rs:74:17
  45:     0x7fafad820259 - start_thread
  46:     0x7fafad7355e3 - __GI___clone
  47:                0x0 - <unknown>

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/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.55.0-nightly (74ef0c3e4 2021-07-16) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis

query stack during panic:
#0 [typeck] type-checking `<impl at /home/matthias/vcs/github/glacier/fixed/74761.rs:8:1: 12:2>::f`
end of query stack
error: aborting due to 3 previous errors; 1 warning emitted

Some errors have detailed explanations: E0207, E0658.
For more information about an error, try `rustc --explain E0207`.