'assertion failed: !self.dead.contains(&id)' panic since 0.2.46

[MaulingMonkey]

Describe the Bug

wasm-bindgen panics building MaulingMonkey/rust_wasm_sample@ff3bbed when invoked by wasm-pack build --dev with the following message:

C:\local\rust_wasm_sample>wasm-pack build --dev
[INFO]: Checking for the Wasm target...
[INFO]: Compiling to Wasm...
   Compiling rust_wasm_sample v0.1.0 (C:\local\rust_wasm_sample)
    Finished dev [unoptimized + debuginfo] target(s) in 0.40s
thread 'main' panicked at 'assertion failed: !self.dead.contains(&id)', C:\Users\Mike\.cargo\registry\src\github.com-1ecc6299db9ec823\walrus-0.8.0\src\tombstone_arena.rs:139:9
stack backtrace:
   0: <unknown>
      ...
  19: <unknown>
  20: BaseThreadInitThunk
  21: RtlUserThreadStart
Error: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit code: 101

This doesn't happen without --dev, possibly because the asserts are getting compiled out? I'm having trouble figuring out how to build wasm-bindgen from source to get symbols / a useful stack trace...

Steps to Reproduce

git clone https://github.com/MaulingMonkey/rust_wasm_sample.git
cd rust_wasm_sample
git checkout ff3bbedbcf3b717a0ae
:: Optionally, specify a specific version of wasm-bindgen in Cargo.toml
wasm-pack build --dev

Cargo.toml [dependencies]	Result
wasm-bindgen = "=0.2.45"	OK
wasm-bindgen = "=0.2.46"	Panic
wasm-bindgen = "=0.2.47"	Panic

Additional Context

wasm-pack version	0.8.1
rustc version	rustc 1.35.0 (3c235d560 2019-05-20)
host toolchain	stable-x86_64-pc-windows-msvc

Command line according to procmon, which I've confirmed also panics:

"%LOCALAPPDATA%\.wasm-pack\wasm-bindgen-a9955440c81117c8\wasm-bindgen.exe" C:\local\rust_wasm_sample\target\wasm32-unknown-unknown\debug\rust_wasm_sample.wasm --out-dir .\pkg --typescript --browser --debug

[lineCode]

I have the same issue

[spencercw]

I am getting the same panic, although I can't reproduce it with your example. It seems to happen when trying to use web-sys for me.

lib.rs:

use web_sys::console;

Dependencies:

wasm-bindgen = "=0.2.47"
web-sys = { version = "=0.3.24", features = ["console"] }

Build output:

$ RUST_BACKTRACE=1 wasm-pack build
[INFO]: Checking for the Wasm target...
[INFO]: Compiling to Wasm...
    Finished release [optimized] target(s) in 0.07s
:-) [WARN]: origin crate has no README
[INFO]: Installing wasm-bindgen...
thread 'main' panicked at 'assertion failed: !self.dead.contains(&id)', /usr/local/cargo/registry/src/github.com-1ecc6299db9ec823/walrus-0.8.0/src/tombstone_arena.rs:139:9
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: std::panicking::rust_panic_with_hook
   5: std::panicking::begin_panic
   6: <walrus::tombstone_arena::TombstoneArena<T> as core::ops::index::IndexMut<id_arena::Id<T>>>::index_mut
   7: wasm_bindgen_cli_support::js::Context::finalize
   8: wasm_bindgen_cli_support::Bindgen::_generate
   9: wasm_bindgen::main
  10: std::rt::lang_start::{{closure}}
  11: std::panicking::try::do_call
  12: __rust_maybe_catch_panic
  13: std::rt::lang_start_internal
  14: main
Error: Running the wasm-bindgen CLI
Caused by: failed to execute `wasm-bindgen`: exited with exit code: 101

[alexcrichton]

Thanks for the report, definitely a bug in the tooling! This should be fixed by #1617