Compiling playground v0.0.1 (/playground)
[ERROR rustc_mir::transform::qualify_consts] old validator: []
[ERROR rustc_mir::transform::qualify_consts] new validator: [(src/lib.rs:5:24: 5:26, "LiveDrop")]
error: internal compiler error: src/librustc_mir/transform/qualify_consts.rs:1038: Disagreement between legacy and dataflow-based const validators.
    After filing an issue, use `-Zsuppress-const-validation-back-compat-ice` to compile your code.
 --> src/lib.rs:4:5
  |
4 | /     pub const EMPTY: Self = Slice ({
5 | |         let v: &[T] = &[];
6 | |         v
7 | |     });
  | |_______^

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:871:9
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:76
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:60
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1028
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1412
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:64
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:196
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:210
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:477
  12: std::panicking::begin_panic
  13: rustc_errors::HandlerInner::span_bug
  14: rustc_errors::Handler::span_bug
  15: rustc::util::bug::opt_span_bug_fmt::{{closure}}
  16: rustc::ty::context::tls::with_opt::{{closure}}
  17: rustc::ty::context::tls::with_context_opt
  18: rustc::ty::context::tls::with_opt
  19: rustc::util::bug::opt_span_bug_fmt
  20: rustc::util::bug::span_bug_fmt
  21: rustc_mir::transform::qualify_consts::Checker::check_const
  22: rustc_mir::transform::qualify_consts::mir_const_qualif
  23: rustc::ty::query::__query_compute::mir_const_qualif
  24: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::mir_const_qualif>::compute
  25: rustc::dep_graph::graph::DepGraph::with_task_impl
  26: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  27: rustc_mir::transform::mir_validated
  28: rustc::ty::query::__query_compute::mir_validated
  29: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::mir_validated>::compute
  30: rustc::dep_graph::graph::DepGraph::with_task_impl
  31: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  32: rustc_mir::borrow_check::mir_borrowck
  33: rustc::ty::query::__query_compute::mir_borrowck
  34: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::mir_borrowck>::compute
  35: rustc::dep_graph::graph::DepGraph::with_task_impl
  36: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  37: rustc::ty::<impl rustc::ty::context::TyCtxt>::par_body_owners
  38: rustc::util::common::time
  39: rustc_interface::passes::analysis
  40: rustc::ty::query::__query_compute::analysis
  41: rustc::dep_graph::graph::DepGraph::with_task_impl
  42: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
  43: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
  44: rustc_interface::passes::create_global_ctxt::{{closure}}
  45: rustc_interface::interface::run_compiler_in_existing_thread_pool
  46: std::thread::local::LocalKey<T>::with
  47: scoped_tls::ScopedKey<T>::set
  48: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 1.40.0-nightly (22bc9e1d9 2019-09-30) running on x86_64-unknown-linux-gnu

note: compiler flags: -C codegen-units=1 -C debuginfo=2 --crate-type lib

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

query stack during panic:
#0 [mir_const_qualif] processing `Slice::<'a, T>::EMPTY`
#1 [mir_validated] processing `Slice::<'a, T>::EMPTY`
#2 [mir_borrowck] processing `Slice::<'a, T>::EMPTY`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

error: could not compile `playground`.

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