error: internal compiler error: librustc/hir/def.rs:289: attempted .def_id() on invalid def: Err

[upsuper]

Having the following Cargo.toml:

[package]
name = "ice-test"
version = "0.1.0"
authors = ["Xidorn Quan <me@upsuper.org>"]
edition = "2018"

[lib]
crate-type = ["cdylib"]

[dependencies]
wasm-bindgen = { git = "https://github.com/rustwasm/wasm-bindgen" }

[dependencies.web-sys]
git = "https://github.com/rustwasm/wasm-bindgen"
features = [
    "Event",
    "UiEvent",
]

and the following lib.rs:

use wasm_bindgen::prelude::*;
use web_sys::KeyboardEvent;

pub fn foo() {
    let a: KeyboardEvent;
}

with the following command:

cargo +nightly build --target wasm32-unknown-unknown

The compiler panics as follow:

error: internal compiler error: librustc/hir/def.rs:289: attempted .def_id() on invalid def: Err
                                                                                
thread 'main' panicked at 'Box<Any>', librustc_errors/lib.rs:586:9              
stack backtrace:                                                                
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace                 
   1: std::sys_common::backtrace::print                                         
   2: std::panicking::default_hook::{{closure}}                                 
   3: std::panicking::default_hook                                              
   4: rustc::util::common::panic_hook                                           
   5: std::panicking::rust_panic_with_hook                                      
   6: std::panicking::begin_panic                                               
   7: rustc_errors::Handler::bug                                                
   8: rustc::util::bug::opt_span_bug_fmt::{{closure}}                           
   9: rustc::ty::context::tls::with_opt::{{closure}}                            
  10: rustc::ty::context::tls::with_context_opt                                 
  11: rustc::ty::context::tls::with_opt                                         
  12: rustc::util::bug::opt_span_bug_fmt                                        
  13: rustc::util::bug::bug_fmt                                                 
  14: rustc::middle::dead::MarkSymbolVisitor::handle_definition                 
  15: rustc::hir::intravisit::walk_ty                                           
  16: rustc::hir::intravisit::walk_block                                        
  17: <rustc::middle::dead::MarkSymbolVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr
  18: <rustc::middle::dead::MarkSymbolVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_nested_body
  19: rustc::hir::intravisit::walk_item                                         
  20: rustc::middle::dead::check_crate                                          
  21: rustc::util::common::time                                                 
  22: rustc::ty::context::tls::enter_context                                    
  23: <std::thread::local::LocalKey<T>>::with                                   
  24: rustc::ty::context::TyCtxt::create_and_enter                              
  25: rustc_driver::driver::compile_input                                       
  26: rustc_driver::run_compiler_with_pool                                      
  27: rustc_driver::driver::spawn_thread_pool                                   
  28: rustc_driver::run_compiler                                                
  29: <scoped_tls::ScopedKey<T>>::set                                           
  30: syntax::with_globals                                                      
  31: __rust_maybe_catch_panic                                                  
  32: rustc_driver::run                                                         
  33: rustc_driver::main                                                        
  34: std::rt::lang_start::{{closure}}                                          
  35: std::panicking::try::do_call                                              
  36: __rust_maybe_catch_panic                                                  
  37: std::rt::lang_start_internal                                              
  38: main                                                                      
query stack during panic:                                                       
end of query stack                                                              
error: aborting due to previous error                   

Meta:

rustc 1.30.0-nightly (2ab3eba30 2018-09-14)
binary: rustc
commit-hash: 2ab3eba30741652ba538bc2fc2bba9d81a5c84c6
commit-date: 2018-09-14
host: x86_64-apple-darwin
release: 1.30.0-nightly
LLVM version: 8.0

[upsuper]

This is an interesting bug that, if I comment out the unused definition, then this doesn't happen.

If I comment out the use wasm_bindgen::prelude::*;, compiler reports:

error[E0432]: unresolved import `web_sys::KeyboardEvent`

(but not panic)

This is a reduced example. In my project, the compiler panics with some different information, mentioning MIR, but also mentions DefId, so maybe they have the same root cause.

[upsuper]

Also, it doesn't seem to be specific to wasm target. With --target wasm32-unknown-unknown removed, the same panic still happens.

[upsuper]

It seems this has been fixed in the latest Nightly...