xilem_html: called Option::unwrap() on a None value

[jplatte]

To reproduce:

1. Check out jplatte/caniuse.rs@151d9e1
2. Run cargo xtask serve
3. Open http://localhost:8000 in a browser
4. Type he into the search bar

panicked at 'called `Option::unwrap()` on a `None` value', /home/jplatte/.cargo/git/checkouts/xilem-031d790027f85a11/9ec2b46/crates/xilem_html/src/view.rs:101:1

Stack:

__wbg_get_imports/imports.wbg.__wbg_new_abda76e883ba8a5f/<@http://localhost:8000/caniuse_rs.js:324:25
logError@http://localhost:8000/caniuse_rs.js:218:22
__wbg_get_imports/imports.wbg.__wbg_new_abda76e883ba8a5f@http://localhost:8000/caniuse_rs.js:323:70
console_error_panic_hook::Error::new::h27abc4bf87348d72@http://localhost:8000/caniuse_rs.wasm:wasm-function[2834]:0x18304c
console_error_panic_hook::hook_impl::h43ba58051cd1388d@http://localhost:8000/caniuse_rs.wasm:wasm-function[531]:0x128b63
console_error_panic_hook::hook::h9887356760a490bc@http://localhost:8000/caniuse_rs.wasm:wasm-function[3186]:0x187c38
core::ops::function::Fn::call::h6d7dc1bd32174f07@http://localhost:8000/caniuse_rs.wasm:wasm-function[2673]:0x1808cd
std::panicking::rust_panic_with_hook::h4f13c7ea06df5ea7@http://localhost:8000/caniuse_rs.wasm:wasm-function[1131]:0x153b59
std::panicking::begin_panic_handler::{{closure}}::h875ead8fb0e54a1b@http://localhost:8000/caniuse_rs.wasm:wasm-function[1468]:0x162eca
std::sys_common::backtrace::__rust_end_short_backtrace::hdbc4415a966db8e6@http://localhost:8000/caniuse_rs.wasm:wasm-function[3481]:0x18a2ac
rust_begin_unwind@http://localhost:8000/caniuse_rs.wasm:wasm-function[2400]:0x17b9aa
core::panicking::panic_fmt::h3ac518bea88a26d3@http://localhost:8000/caniuse_rs.wasm:wasm-function[3028]:0x185c0b
core::panicking::panic::he7d1dc94b47dab2b@http://localhost:8000/caniuse_rs.wasm:wasm-function[2671]:0x18084e
core::option::Option<T>::unwrap::ha4e9a4f9516eb2be@http://localhost:8000/caniuse_rs.wasm:wasm-function[1729]:0x16b66c
<V as xilem_html::view::ViewSequence<T,A>>::rebuild::h703ac3023a0b4a91@http://localhost:8000/caniuse_rs.wasm:wasm-function[1505]:0x1645a9
<xilem_html::view::Either<V1,V2> as xilem_html::view::ViewSequence<T,A>>::rebuild::h37524240aec8e392@http://localhost:8000/caniuse_rs.wasm:wasm-function[144]:0xe4a34
<alloc::vec::Vec<VT> as xilem_html::view::ViewSequence<T,A>>::rebuild::he261c11a5222fea6@http://localhost:8000/caniuse_rs.wasm:wasm-function[139]:0xe227e
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::{{closure}}::hdb6d8a2092696972@http://localhost:8000/caniuse_rs.wasm:wasm-function[2215]:0x177ab8
xilem_html::context::Cx::with_id::hc06e00db7b9b037f@http://localhost:8000/caniuse_rs.wasm:wasm-function[2119]:0x175753
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::h79ef49156e802e83@http://localhost:8000/caniuse_rs.wasm:wasm-function[72]:0xacb9f
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::rebuild::hd1b3dd34f133147e@http://localhost:8000/caniuse_rs.wasm:wasm-function[2053]:0x173dcf
<V as xilem_html::view::ViewSequence<T,A>>::rebuild::hefbd7aeecd1405e6@http://localhost:8000/caniuse_rs.wasm:wasm-function[1450]:0x16236b
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::rebuild::h850edb6ff1963b62@http://localhost:8000/caniuse_rs.wasm:wasm-function[1207]:0x157765
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::{{closure}}::h7d1c1415c6a21e9e@http://localhost:8000/caniuse_rs.wasm:wasm-function[2199]:0x1774f8
xilem_html::context::Cx::with_id::h6c6da227a22e67e7@http://localhost:8000/caniuse_rs.wasm:wasm-function[2110]:0x1753e1
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::hfbd1b4127bf100c6@http://localhost:8000/caniuse_rs.wasm:wasm-function[87]:0xc0cae
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::rebuild::hd8fa718e58ca4c35@http://localhost:8000/caniuse_rs.wasm:wasm-function[2054]:0x173e33
<V as xilem_html::view::ViewSequence<T,A>>::rebuild::he6cf050c5a893576@http://localhost:8000/caniuse_rs.wasm:wasm-function[1449]:0x1622c5
<alloc::vec::Vec<VT> as xilem_html::view::ViewSequence<T,A>>::rebuild::h1d5c8d5bb38b5065@http://localhost:8000/caniuse_rs.wasm:wasm-function[138]:0xe1a82
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::{{closure}}::haf75742e4cdce3c4@http://localhost:8000/caniuse_rs.wasm:wasm-function[2207]:0x1777d8
xilem_html::context::Cx::with_id::h25134a75fb6d0cf9@http://localhost:8000/caniuse_rs.wasm:wasm-function[2103]:0x175133
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::h5ce3dde0c3f17596@http://localhost:8000/caniuse_rs.wasm:wasm-function[70]:0xaa0db
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::rebuild::h6f8797c1a3ba9197@http://localhost:8000/caniuse_rs.wasm:wasm-function[2050]:0x173ca3
<V as xilem_html::view::ViewSequence<T,A>>::rebuild::h8c2495bae530a2dd@http://localhost:8000/caniuse_rs.wasm:wasm-function[1440]:0x161cea
<caniuse_rs::either::Either3<V1,V2,V3> as xilem_html::view::ViewSequence<T,A>>::rebuild::h32910340dfcb300e@http://localhost:8000/caniuse_rs.wasm:wasm-function[93]:0xc7574
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::rebuild::h0b23fe7227f9e5cd@http://localhost:8000/caniuse_rs.wasm:wasm-function[1201]:0x15730a
<caniuse_rs::either::Either3<V1,V2,V3> as xilem_html::view::ViewSequence<T,A>>::rebuild::hacfa139821938acb@http://localhost:8000/caniuse_rs.wasm:wasm-function[157]:0xe9bbf
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::{{closure}}::hd699b74762b0df24@http://localhost:8000/caniuse_rs.wasm:wasm-function[2213]:0x177a00
xilem_html::context::Cx::with_id::h25a7bb8f96f2439b@http://localhost:8000/caniuse_rs.wasm:wasm-function[2104]:0x175195
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::hef4d11aa00abe777@http://localhost:8000/caniuse_rs.wasm:wasm-function[83]:0xbb704
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::rebuild::ha22503a13f142a31@http://localhost:8000/caniuse_rs.wasm:wasm-function[2051]:0x173d07
<V as xilem_html::view::ViewSequence<T,A>>::rebuild::had6835093d51d113@http://localhost:8000/caniuse_rs.wasm:wasm-function[1442]:0x161e37
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::rebuild::h2b4614dfb3efc8e9@http://localhost:8000/caniuse_rs.wasm:wasm-function[1204]:0x15755b
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::{{closure}}::h255d733b12ee1247@http://localhost:8000/caniuse_rs.wasm:wasm-function[2190]:0x1771bc
xilem_html::context::Cx::with_id::h9b371f762466f73d@http://localhost:8000/caniuse_rs.wasm:wasm-function[2116]:0x17562d
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::rebuild::h5b0b6481dfb6e7f9@http://localhost:8000/caniuse_rs.wasm:wasm-function[69]:0xa8b76
<xilem_html::element::elements::Main<ViewSeq> as xilem_html::view::View<T_,A_>>::rebuild::hdb9fadd76598af11@http://localhost:8000/caniuse_rs.wasm:wasm-function[2060]:0x17408b
<xilem_html::app::App<T,V,F> as xilem_html::app::AppRunner>::handle_message::hb2fbc62780306995@http://localhost:8000/caniuse_rs.wasm:wasm-function[252]:0x102f67
xilem_html::context::MessageThunk::push_message::h4ac8777da238898b@http://localhost:8000/caniuse_rs.wasm:wasm-function[1119]:0x15311b
<xilem_html::event::OnEvent<E,V,F> as xilem_html::view::View<T,A>>::build::{{closure}}::hb767d9056dde59c8@http://localhost:8000/caniuse_rs.wasm:wasm-function[1570]:0x166a0d
<dyn core::ops::function::FnMut<(&A,)>+Output = R as wasm_bindgen::closure::WasmClosure>::describe::invoke::h97e9d7d3b1ade7cd@http://localhost:8000/caniuse_rs.wasm:wasm-function[977]:0x14b0ae
__wbg_adapter_16@http://localhost:8000/caniuse_rs.js:247:18
real@http://localhost:8000/caniuse_rs.js:201:24
EventListener.handleEvent*__wbg_get_imports/imports.wbg.__wbg_addEventListener_a5963e26cd7b176b/<@http://localhost:8000/caniuse_rs.js:532:29
handleError@http://localhost:8000/caniuse_rs.js:265:22
__wbg_get_imports/imports.wbg.__wbg_addEventListener_a5963e26cd7b176b@http://localhost:8000/caniuse_rs.js:531:83
web_sys::features::gen_EventTarget::EventTarget::add_event_listener_with_callback_and_add_event_listener_options::h92e6149a74053ae2@http://localhost:8000/caniuse_rs.wasm:wasm-function[567]:0x12c275
gloo_events::EventListener::raw_new::hb1d3fac9f2700c4e@http://localhost:8000/caniuse_rs.wasm:wasm-function[394]:0x1197df
gloo_events::EventListener::new::{{closure}}::hfb15f6de51805b15@http://localhost:8000/caniuse_rs.wasm:wasm-function[971]:0x14aaee
std::thread::local::LocalKey<T>::try_with::ha7f1cd495a121d84@http://localhost:8000/caniuse_rs.wasm:wasm-function[344]:0x112a4c
std::thread::local::LocalKey<T>::with::ha25abea5ab0c3152@http://localhost:8000/caniuse_rs.wasm:wasm-function[554]:0x12aea5
gloo_events::EventListener::new::h8f2e5d6050e28b3b@http://localhost:8000/caniuse_rs.wasm:wasm-function[714]:0x138ba7
<xilem_html::event::OnEvent<E,V,F> as xilem_html::view::View<T,A>>::build::h6965fa3e958b910f@http://localhost:8000/caniuse_rs.wasm:wasm-function[155]:0xe9034
<xilem_html::event::events::OnInput<T,A,V,F,OA> as xilem_html::view::View<T,A>>::build::h28c3e82f1e351a19@http://localhost:8000/caniuse_rs.wasm:wasm-function[2781]:0x18236a
<V as xilem_html::view::ViewSequence<T,A>>::build::h4158e2e06ccf9658@http://localhost:8000/caniuse_rs.wasm:wasm-function[236]:0xff92b
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::build::h9c0068cfd11082e8@http://localhost:8000/caniuse_rs.wasm:wasm-function[240]:0x100675
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::{{closure}}::h127494c3a8dd5651@http://localhost:8000/caniuse_rs.wasm:wasm-function[2352]:0x17a9a3
xilem_html::context::Cx::with_new_id::h83854c07f83250a4@http://localhost:8000/caniuse_rs.wasm:wasm-function[1264]:0x15a336
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::hb9b9c1c6ae944c44@http://localhost:8000/caniuse_rs.wasm:wasm-function[125]:0xdaf08
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::build::h185925b41262e684@http://localhost:8000/caniuse_rs.wasm:wasm-function[2758]:0x181dcc
<V as xilem_html::view::ViewSequence<T,A>>::build::h1e29596e46fcdbea@http://localhost:8000/caniuse_rs.wasm:wasm-function[958]:0x149daf
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::build::h4dc73693a2cd716a@http://localhost:8000/caniuse_rs.wasm:wasm-function[534]:0x128fef
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::{{closure}}::h6c3dd079c0c49188@http://localhost:8000/caniuse_rs.wasm:wasm-function[2363]:0x17ad55
xilem_html::context::Cx::with_new_id::hcfdd931836917f28@http://localhost:8000/caniuse_rs.wasm:wasm-function[1269]:0x15a70b
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::hc52a43a992242fa7@http://localhost:8000/caniuse_rs.wasm:wasm-function[137]:0xe1163
<xilem_html::element::elements::Div<ViewSeq> as xilem_html::view::View<T_,A_>>::build::hd30d367e925935ba@http://localhost:8000/caniuse_rs.wasm:wasm-function[2767]:0x181ffd
<V as xilem_html::view::ViewSequence<T,A>>::build::h014c455f65f3b306@http://localhost:8000/caniuse_rs.wasm:wasm-function[1046]:0x14f10f
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::{{closure}}::h38c86573d113ca68@http://localhost:8000/caniuse_rs.wasm:wasm-function[2358]:0x17aba7
xilem_html::context::Cx::with_new_id::hcc2cbeb37a6764c1@http://localhost:8000/caniuse_rs.wasm:wasm-function[1268]:0x15a646
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::hbe76d5f06bf1f59b@http://localhost:8000/caniuse_rs.wasm:wasm-function[136]:0xe093f
<xilem_html::element::elements::Header<ViewSeq> as xilem_html::view::View<T_,A_>>::build::h013b637f909bb0e5@http://localhost:8000/caniuse_rs.wasm:wasm-function[2775]:0x1821f0
<V as xilem_html::view::ViewSequence<T,A>>::build::haf66c7ce9f9eda8a@http://localhost:8000/caniuse_rs.wasm:wasm-function[1047]:0x14f1fe
<(V0,V1) as xilem_html::view::ViewSequence<T,A>>::build::habb10c8714a92368@http://localhost:8000/caniuse_rs.wasm:wasm-function[629]:0x1319b4
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::{{closure}}::h72062840b3ea4b4f@http://localhost:8000/caniuse_rs.wasm:wasm-function[2364]:0x17adab
xilem_html::context::Cx::with_new_id::h242f0a0485ac6697@http://localhost:8000/caniuse_rs.wasm:wasm-function[1258]:0x159e9c
<xilem_html::element::Element<El,Children> as xilem_html::view::View<T,A>>::build::hbbdb89055df7b294@http://localhost:8000/caniuse_rs.wasm:wasm-function[131]:0xde051
<xilem_html::element::elements::Main<ViewSeq> as xilem_html::view::View<T_,A_>>::build::h23d7270daf43f452@http://localhost:8000/caniuse_rs.wasm:wasm-function[2771]:0x1820f7
xilem_html::app::AppInner<T,V,F>::ensure_app::hb0f6f25139ff428e@http://localhost:8000/caniuse_rs.wasm:wasm-function[313]:0x10db54
xilem_html::app::App<T,V,F>::run::hc895366a05421a85@http://localhost:8000/caniuse_rs.wasm:wasm-function[1017]:0x14d76e
caniuse_rs::run::hd6d283b75717c90e@http://localhost:8000/caniuse_rs.wasm:wasm-function[954]:0x149a46
run@http://localhost:8000/caniuse_rs.wasm:wasm-function[3245]:0x188828
run@http://localhost:8000/caniuse_rs.js:256:14
main@http://localhost:8000/caniuse_rs.js:687:13
async*@http://localhost:8000/caniuse_rs.js:689:9
@http://localhost:8000/caniuse_rs.js:697:3


caniuse_rs.js:318:25

[Philipp-M]

Is it anyhow possible that line numbers are added in the trace, so that it's easier to debug?

[jplatte]

I don't know for sure. For xtask serve, I use wasm-pack build --target web --dev. Maybe it has other flags besides --dev for debugging (not at a computer now so can't check). I didn't customize the dev profile in Cargo.toml, so from rustc's perspective all debugging info should already be enabled.

[jplatte]

Looks like line numbers in stack traces need better DWARF support in wasm-bindgen, which is blocked on rustwasm/wasm-bindgen#3483, itself blocked on rustwasm/walrus#247.

[Philipp-M]

As there's a lot of bug-fixes in #141 as well, could you try it out with that PR, maybe it fixes this issue?

[jplatte]

Will do!

[jplatte]

Looks like this is indeed fixed by #141 :)