ICE: Shadowing a unit-like enum in a closure crashes compiler

[Moredread]

Shadowing a unit-like enum in a closure crashes compiler.

I tried this code:

struct Test;

fn main() {
    || {
        let Test = 1;
    };
}

I expected to see this happen: Failure message E0413

Instead, this happened: Compiler crash

driver.rs:5:13: 5:17 error: declaration of `Test` shadows an enum variant or unit-like struct in scope [E0413]
driver.rs:5         let Test = 1;
                        ^~~~
driver.rs:5:13: 5:17 help: run `rustc --explain E0413` to see a detailed explanation
error: internal compiler error: ../src/librustc/middle/mem_categorization.rs:614: Def::Err in memory categorization
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 'Box<Any>', ../src/libsyntax/errors/mod.rs:576
note: Run with `RUST_BACKTRACE=1` for a backtrace.

Meta

rustc --version --verbose:

rustc 1.10.0-nightly (62e2b2fb7 2016-05-06)
binary: rustc
commit-hash: 62e2b2fb7acf5f8331781cd7128c754ed1b66c4f
commit-date: 2016-05-06
host: x86_64-unknown-linux-gnu
release: 1.10.0-nightly

Backtrace:

thread 'rustc' panicked at 'Box<Any>', ../src/libsyntax/errors/mod.rs:576
stack backtrace:
   1:     0x7f95e967bd10 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
   2:     0x7f95e968958b - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
   3:     0x7f95e968912c - std::panicking::default_hook::hc2c969e7453d080c
   4:     0x7f95e964e8cf - std::sys_common::unwind::begin_unwind_inner::h30e12d15ce2b2e25
   5:     0x7f95e4ca6717 - std::sys_common::unwind::begin_unwind::h24c4c0fa2cfe995a
   6:     0x7f95e4ca607e - syntax::errors::Handler::bug::h4846e60601033e50
   7:     0x7f95e5d2fab2 - rustc::session::opt_span_bug_fmt::_$u7b$$u7b$closure$u7d$$u7d$::hf0fb5697f8f25f40
   8:     0x7f95e5d2f942 - rustc::session::opt_span_bug_fmt::hc581ba88c4e2ec53
   9:     0x7f95e5d47826 - rustc::session::bug_fmt::had96c08cb43bd8a1
  10:     0x7f95e5ebecb0 - rustc::middle::mem_categorization::MemCategorizationContext::cat_def::h1e6d1d71a3ac3d06
  11:     0x7f95e5ebcce9 - rustc::middle::mem_categorization::MemCategorizationContext::cat_pattern_::h688ac5141fed7601
  12:     0x7f95e5eba413 - rustc::middle::expr_use_visitor::ExprUseVisitor::walk_pat::h95254f9d39fba4a1
  13:     0x7f95e5eb5cf3 - rustc::middle::expr_use_visitor::ExprUseVisitor::walk_irrefutable_pat::h7304094e79d13564
  14:     0x7f95e5eb8d46 - rustc::middle::expr_use_visitor::ExprUseVisitor::walk_stmt::h8bc9b54fe3fcb6f0
  15:     0x7f95e5eb7f0e - rustc::middle::expr_use_visitor::ExprUseVisitor::walk_expr::h9cca31560139037e
  16:     0x7f95e5eb5e84 - rustc::middle::expr_use_visitor::ExprUseVisitor::consume_expr::ha16e99aa14e61262
  17:     0x7f95e5eb5b65 - rustc::middle::expr_use_visitor::ExprUseVisitor::walk_fn::h5a4a2ab4ebcdb73a
  18:     0x7f95e6cb635d - _<check..upvar..AdjustBorrowKind<'a, 'tcx> as rustc..hir..intravisit..Visitor<'v>>::visit_fn::hba13755c61d6d401
  19:     0x7f95e6cb5e48 - rustc::hir::intravisit::walk_expr::h4743b97a2ee4072c
  20:     0x7f95e6c14a5a - rustc_typeck::check::check_bare_fn::h7e4c2ad58d1814dd
  21:     0x7f95e6c12196 - rustc_typeck::check::check_item_body::h7ffec660fc242796
  22:     0x7f95e6c0a011 - rustc_typeck::check::check_item_bodies::ha729008a2e67410e
  23:     0x7f95e6c02012 - rustc_typeck::check_crate::hb08ba31a6a5f65b5
  24:     0x7f95e9bd0860 - rustc_driver::driver::phase_3_run_analysis_passes::_$u7b$$u7b$closure$u7d$$u7d$::hfdd8d88ff571b474
  25:     0x7f95e9bce8be - rustc::ty::context::TyCtxt::create_and_enter::ha551c2427049829f
  26:     0x7f95e9b9a285 - rustc_driver::driver::compile_input::h0629572e6f316b31
  27:     0x7f95e9b8a4fd - rustc_driver::run_compiler::h8902aebf8b1849a8
  28:     0x7f95e9b877bd - std::sys_common::unwind::try::try_fn::h4c74456035d0fcc7
  29:     0x7f95e96794eb - __rust_try
  30:     0x7f95e967947d - std::sys_common::unwind::inner_try::h47a4d9cd4a369dcd
  31:     0x7f95e9b881ea - _<F as std..boxed..FnBox<A>>::call_box::h27f542a39f1d61ef
  32:     0x7f95e96876f4 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  33:     0x7f95e1424473 - start_thread
  34:     0x7f95e92e5acc - clone
  35:                0x0 - <unknown>

[Moredread]

The same code crashes also on stable, at a different code point.

thread 'rustc' panicked at 'Def::Err in memory categorization', ../src/librustc/middle/mem_categorization.rs:613
stack backtrace:
   1:     0x7fb3f2270330 - sys::backtrace::tracing::imp::write::h3675b4f0ca767761Xcv
   2:     0x7fb3f227968b - panicking::default_handler::_$u7b$$u7b$closure$u7d$$u7d$::closure.44519
   3:     0x7fb3f22791e3 - panicking::default_handler::h18faf4fbd296d909lSz
   4:     0x7fb3f223d9ac - sys_common::unwind::begin_unwind_inner::hfb5d07d6e405c6bbg1t
   5:     0x7fb3ef4c120f - sys_common::unwind::begin_unwind::h17349651284183375827
   6:     0x7fb3ef4ffc45 - middle::mem_categorization::MemCategorizationContext<'t, 'a, 'tcx>::cat_def::hdeb344a5491bba80aeK
   7:     0x7fb3ef4fdbc2 - middle::mem_categorization::MemCategorizationContext<'t, 'a, 'tcx>::cat_pattern_::h2171199047159068738
   8:     0x7fb3ef4fa833 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::walk_pat::hf4d5b3d8cb6f67ecUgh
   9:     0x7fb3ef4f5353 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::walk_irrefutable_pat::h5668c6e2ce3263877bh
  10:     0x7fb3ef4f8ad6 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::walk_stmt::h3e8eaabe6a16d9c1lKg
  11:     0x7fb3ef4f7c3e - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::walk_expr::he2c7af9ebce7c88agsg
  12:     0x7fb3ef4f54de - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::consume_expr::h1393a4fb15fc5089Xjg
  13:     0x7fb3ef4f5155 - middle::expr_use_visitor::ExprUseVisitor<'d, 't, 'a, 'tcx>::walk_fn::h8572ed4d964016a4Xeg
  14:     0x7fb3f18af490 - check::upvar::AdjustBorrowKind<'a, 'tcx>.Visitor<'v>::visit_fn::h029e8800c7c40314P4j
  15:     0x7fb3f18af213 - intravisit::walk_expr::h6226208990425569121
  16:     0x7fb3f17f7b0a - check::check_bare_fn::h846d602fffbab51bLDo
  17:     0x7fb3f17f2876 - check::check_item_body::h1bc79a321f78eb96h3o
  18:     0x7fb3f17e932b - check::check_item_bodies::h5671f35c802ef7c1yBo
  19:     0x7fb3f17e0bb3 - check_crate::h7bb847abc9f256eeeCC
  20:     0x7fb3f279c667 - driver::phase_3_run_analysis_passes::_$u7b$$u7b$closure$u7d$$u7d$::closure.28550
  21:     0x7fb3f279ac04 - middle::ty::context::ctxt<'tcx>::create_and_enter::h16192426302205697189
  22:     0x7fb3f27976ef - driver::phase_3_run_analysis_passes::h10920926650053012691
  23:     0x7fb3f276aa15 - driver::compile_input::h7ae6a86e23de0774Hca
  24:     0x7fb3f2759b47 - run_compiler::hb0408bcf47642fe6mPc
  25:     0x7fb3f27572c1 - sys_common::unwind::try::try_fn::h7614151098073783683
  26:     0x7fb3f226dd1b - __rust_try
  27:     0x7fb3f22661fd - sys_common::unwind::inner_try::hadd81c754a64f07ciYt
  28:     0x7fb3f2757b10 - boxed::F.FnBox<A>::call_box::h18261575856772421581
  29:     0x7fb3f2277c59 - sys::thread::Thread::new::thread_start::h9bc812305b5e01feFPy
  30:     0x7fb3eb541473 - start_thread
  31:     0x7fb3f1eefacc - clone
  32:                0x0 - <unknown>

[Moredread]

This seems to have been fixed, I don't get the error on nightly anymore. I haven't bisected what fixed it though.

[jseyfried]

cc me

[Stebalien]

@sanxiyn this appears to have been fixed.

[Mark-Simulacrum]

E-needstest.