ICE - path not fully resolved

This code triggers an ICE:

use std::collections::*;

pub enum A {a}

fn main() {
    let xs = HashSet::new();
    xs.contains(&A::DoesntExist);
}

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
thread 'rustc' panicked at 'path not fully resolved: PathResolution { base_def: DefTy(DefId { krate: 0, node: 5 }, true), last_private: LastMod(AllPublic), depth: 1 }', C:/bot/slave/nightly-dist-rustc-win-gnu-64/build/src/librustc\middle\def.rs:81

stack backtrace:
   1:         0x63cb9009 - sys::backtrace::write::hbf05e078e24af39fhos
   2:         0x63cc24b6 - rt::unwind::register::h82ac513e119c8c9fX2v
   3:         0x63c85216 - rt::unwind::begin_unwind_inner::h1126581147898f676Zv
   4:         0x63c85bc7 - rt::unwind::begin_unwind_fmt::h169e83bb23b1c4adcZv
   5:         0x6d5af856 - middle::ty::resolve_expr::h620f249100bb5a69Zp9
   6:         0x6d6fb666 - middle::ty::expr_kind::h3f5acaec9f666cfa5r9
   7:         0x6d6fb459 - middle::ty::expr_is_lval::he5805dd8c49ad3142q9
   8:           0x7b5b1a - check::UnresolvedTypeAction...std..clone..Clone::clone::ha3dba94ad03aaf061Rp
   9:           0x78e029 - check::callee::CallResolution<'tcx>.DeferredCallResolution<'tcx>::resolve::h3351210ce535c238Ojm
  10:           0x78f759 - check::callee::CallResolution<'tcx>.DeferredCallResolution<'tcx>::resolve::h3351210ce535c238Ojm
  11:           0x7ba140 - check::may_break::hbb9ba306bd1d5487zEt
  12:           0x7e2cf1 - check::may_break::hbb9ba306bd1d5487zEt
  13:           0x7f3674 - check::check_stmt::h4d316e8fc14d786a2ms
  14:           0x7a53ab - check::GatherLocalsVisitor<'a, 'tcx>.Visitor<'tcx>::visit_item::h7a12a74a153228d9sZn
  15:           0x7888fa - check::FnCtxt<'a, 'tcx>.AstConv<'tcx>::projected_ty::h2e717bd79922c179tWo
  16:           0x79f9fe - check::check_item_types::h6ceed96b60bdb1f7RMn
  17:           0x79da96 - check::check_item_body::hfd06d8a5180c7abadgo
  18:           0x79f644 - check::check_item_types::h6ceed96b60bdb1f7RMn
  19:           0x8569aa - check_crate::h5b156b3b307798df98C
  20:         0x6fca0ff3 - driver::phase_3_run_analysis_passes::h7cdd2757022e69b7GGa
  21:         0x6fc82b40 - driver::compile_input::hd3c2c22595f08a0dQba
  22:         0x6fd36f64 - run_compiler::h240f1371549aa104n6b
  23:         0x6fd34b0f - run::he7af85fec9d5c95635b
  24:         0x6fd34409 - run::he7af85fec9d5c95635b
  25:         0x63cfc8bc - rust_try
  26:         0x63cfc899 - rust_try
  27:         0x63cad929 - rt::unwind::try::inner_try::h4474d627913bcf79ZVv
  28:         0x6fd345d8 - run::he7af85fec9d5c95635b
  29:         0x63cc0674 - sys::process::Command::cwd::ha5f7446f3da2500ftHu
  30:         0x76d759cd - BaseThreadInitThunk

This ICE is especially annoying because rustc doesn't give any other error message. It gives no indication of where the problem is in your code.

rust-lang / rust

ICE - path not fully resolved #26815