error: internal compiler error: unexpected failure (expected item, found foreign item)

[dotnwat]

I'm getting the following error compiling a simple FFI test (backtrace included below). I am creating a reference to a static pointer symbol in a C library. Then, I have a Rust object wrapper and want to create a static instance of that object that points to the pointer defined in the C library. Here is the gist of the library:

pub type MPI_Comm = *c_void;
extern {
   pub static MPI_COMM_WORLD: MPI_Comm;
}

pub struct Comm {
  ptr: ffi::MPI_Comm,
}

pub static COMM_WORLD: Comm = Comm { ptr: ffi::MPI_COMM_WORLD };

Backtrace

error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug.
note: we would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' failed at 'expected item, found foreign item ffi::MPI_COMM_WORLD::MPI_COMM_WORLD (id=47)', /home/nwatkins/rust/rust/src/libsyntax/ast_map.rs:264
stack backtrace:
   1:     0x7f389bbf6320 - rt::backtrace::imp::write::he4a96dd9becae7baQZF::v0.11.pre
   2:     0x7f389bb5e7f0 - rt::unwind::begin_unwind_inner::h429f42930e247ed3TzF::v0.11.pre
   3:     0x7f389bb5da40 - rt::unwind::begin_unwind_fmt::h2658199b4e21bf1d3yF::v0.11.pre
   4:     0x7f389a7d9f70 - ast_map::Map::expect_item::hfd129ba246eef9e7fmw::v0.11.pre
   5:     0x7f389cb333e0 - middle::check_const::CheckItemRecursionVisitor<'a>.Visitor<(*>::visit_expr::h5cd0b6fa8c9a4f2bGTx::v0.11.pre
   6:     0x7f389cb333e0 - middle::check_const::CheckItemRecursionVisitor<'a>.Visitor<(*>::visit_expr::h5cd0b6fa8c9a4f2bGTx::v0.11.pre
   7:     0x7f389cb321e0 - middle::check_const::CheckItemRecursionVisitor<'a>.Visitor<(*>::visit_item::hd092905fe77dd21cLSx::v0.11.pre
   8:     0x7f389cb2d7d0 - middle::check_const::check_item::h95a2cf717ce35925AHx::v0.11.pre
   9:     0x7f389cb306a0 - middle::check_const::check_crate::hb33f792abf387b41bHx::v0.11.pre
  10:     0x7f389cb13c40 - util::common::time::h2370236349741964365::v0.11.pre
  11:     0x7f389cef3780 - driver::driver::phase_3_run_analysis_passes::h6fe36fe1431dcb23Wci::v0.11.pre
  12:     0x7f389ceed280 - driver::driver::compile_input::h002d716c1383702at2h::v0.11.pre
  13:     0x7f389cf90af0 - driver::main_args::closure.92546
  14:     0x7f389cfa7310 - driver::monitor::closure.93721
  15:     0x7f389cfa1750 - task::TaskBuilder::try::closure.93488
  16:     0x7f389c15f1c0 - task::spawn_opts::closure.7382
  17:     0x7f389bbeccd0 - rt::task::Task::run::closure.28450
  18:     0x7f389bc0eaf0 - rust_try
  19:     0x7f389bbecb10 - rt::task::Task::run::h8aff154bc145518aBoD::v0.11.pre
  20:     0x7f389c15ef70 - task::spawn_opts::closure.7355
  21:     0x7f389bbf4d20 - rt::thread::thread_start::ha112b5063324e752M6D::v0.11.pre
  22:     0x7f38998ab0c0 - start_thread
  23:     0x7f389b8292d9 - __clone
  24:                0x0 - <unknown>

[lilyball]

Simpler test case:

extern {
    pub static symbol: ();
}
static CRASH: () = symbol;

[lilyball]

I suspect there's no valid way for this to work, so it should probably just raise an error.

[huonw]

See #9866, and #13325 is vaguely related.

[sanxiyn]

This seems fixed by #18279.