panic assertion failed intermitent crash compiled to WASM and running with libwebkit2gtk on Linux

[kellpossible]

I was referred from rust-lang/hashbrown#194 to report this issue here too

Compiled using wasm-bindgen, via wasm-pack using the web target, and the --dev profile. This code is running in the webkit2gtk 2.28.4-1 browser on Archlinux.

Stack trace:

panicked at 'assertion failed: `(left != right)`
  left: `0`,
 right: `0`', ~/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcore/macros/mod.rs:16:9

<?>.wasm-function[console_error_panic_hook::Error::new::h11710926359e6a99]@[wasm code]
<?>.wasm-function[console_error_panic_hook::hook_impl::h43ac723b12164d7a]@[wasm code]
<?>.wasm-function[console_error_panic_hook::hook::h1509fc86d60f8ecc]@[wasm code]
<?>.wasm-function[core::ops::function::Fn::call::h63e0941c1aa82381]@[wasm code]
<?>.wasm-function[std::panicking::rust_panic_with_hook::h3e6619a8809a443a]@[wasm code]
<?>.wasm-function[rust_begin_unwind]@[wasm code]
<?>.wasm-function[core::panicking::panic_fmt::ha8209066b105fcdd]@[wasm code]
<?>.wasm-function[hashbrown::raw::inner::RawTable<T>::bucket::hfcb3cc32fba2684b]@[wasm code]
<?>.wasm-function[hashbrown::raw::inner::RawTable<T>::insert::h71a2e674faab18bc]@[wasm code]
<?>.wasm-function[indexmap::map::core::IndexMapCore<K,V>::push::h4f42c6dc20fce8fb]@[wasm code]
<?>.wasm-function[indexmap::map::core::IndexMapCore<K,V>::insert_full::h6cc9bd7b0982815d]@[wasm code]
<?>.wasm-function[indexmap::map::IndexMap<K,V,S>::insert_full::he19372e70f82483d]@[wasm code]
<?>.wasm-function[indexmap::map::IndexMap<K,V,S>::insert::h007a7c31241165e3]@[wasm code]
<?>.wasm-function[<indexmap::map::IndexMap<K,V,S> as core::iter::traits::collect::Extend<(K,V)>>::extend::{{closure}}::h396d242148f62446]@[wasm code]
<?>.wasm-function[core::iter::traits::iterator::Iterator::for_each::call::{{closure}}::hbb035c70f8777522]@[wasm code]
<?>.wasm-function[core::iter::adapters::map_fold::{{closure}}::h62be75b9f0a27adf]@[wasm code]
<?>.wasm-function[core::iter::adapters::filter_fold::{{closure}}::h268ff1624341ca8a]@[wasm code]
<?>.wasm-function[core::iter::adapters::map_fold::{{closure}}::hcf5aea4a2ef5e328]@[wasm code]
<?>.wasm-function[core::iter::traits::iterator::Iterator::fold::h853140cd02b11d69]@[wasm code]
<?>.wasm-function[<core::iter::adapters::Map<I,F> as core::iter::traits::iterator::Iterator>::fold::hf5d0ea58d414ae46]@[wasm code]
<?>.wasm-function[<core::iter::adapters::Filter<I,P> as core::iter::traits::iterator::Iterator>::fold::hfe2842f31b010ace]@[wasm code]
<?>.wasm-function[<core::iter::adapters::Map<I,F> as core::iter::traits::iterator::Iterator>::fold::h64e7ef0a45baccd6]@[wasm code]
<?>.wasm-function[core::iter::traits::iterator::Iterator::for_each::h5ba4ea97dae030ca]@[wasm code]
<?>.wasm-function[<indexmap::map::IndexMap<K,V,S> as core::iter::traits::collect::Extend<(K,V)>>::extend::h413750f7b641b695]@[wasm code]
<?>.wasm-function[<indexmap::map::IndexMap<K,V,S> as core::iter::traits::collect::FromIterator<(K,V)>>::from_iter::h49e190a53d106e85]@[wasm code]
<?>.wasm-function[<indexmap::set::IndexSet<T,S> as core::iter::traits::collect::FromIterator<T>>::from_iter::hc8ac9b46dc06688c]@[wasm code]
<?>.wasm-function[core::iter::traits::iterator::Iterator::collect::h6577e1d6120a2276]@[wasm code]
<?>.wasm-function[<yew::virtual_dom::Classes as core::convert::From<&str>>::from::hdb0a0b180f292b8c]@[wasm code]
<?>.wasm-function[<T as core::convert::Into<U>>::into::h22798bc94b25b76c]@[wasm code]

It's possible this may be related to rust-random/rand#1016 Perhaps it's a stability issue in libwebkit2gtk.

[cuviper]

I definitely want to know what's going wrong, but as I mentioned on the hashbrown issue, I don't see how this could be failing due anything indexmap is doing.

[kellpossible]

I've not had the time to create a reproducible example that I can share, this issue appears to be exclusively occurring on libwebkit2gtk, perhaps it's a bug with the webassembly implementation there. After several weeks running my application in chomium and firefox I've yet to reproduce the issue in those browsers. I've also had some rendering issues exclusive to libwebkit2gtk so probably will ditch it at this point and use some other solution.