1951542 - Hit MOZ_CRASH(Should be already computed) at servo/components/style/custom_properties.rs:2093

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Tyson Smith [:tsmith]]

Found with m-c 20250302-2879c26ed4cc (--enable-debug)

This was found by visiting a live website with a debug build.

STR:

• Launch browser and visit site

This issue was triggered by visiting http://shopware.com/. A Pernosco session is available here: https://pernos.co/debug/4pUs_9czXmxY97lBIwncIw/index.html

Hit MOZ_CRASH(Should be already computed) at servo/components/style/custom_properties.rs:2093

0|0|xul.dll|RustMozCrash(char const*, int, char const*)|hg:hg.mozilla.org/mozilla-central:mozglue/static/rust/wrappers.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|18|0x23
0|1|xul.dll|mozglue_static::panic_hook(std::panic::PanicHookInfo*)|hg:hg.mozilla.org/mozilla-central:mozglue/static/rust/lib.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|99|0xf5
0|2|xul.dll|core::ops::function::Fn::call<void (*)(ref$<std::panic::PanicHookInfo>),tuple$<ref$<std::panic::PanicHookInfo> > >(void (**)(std::panic::PanicHookInfo*), std::panic::PanicHookInfo*)|/rustc/4d91de4e48198da2e33413efdcd9cd2cc0c46688/library/core/src/ops/function.rs|79|0x11
0|3|xul.dll|std::panicking::rust_panic_with_hook()|git:github.com/rust-lang/rust:library/std/src/panicking.rs:4d91de4e48198da2e33413efdcd9cd2cc0c46688|836|0xe7
0|4|xul.dll|std::panicking::begin_panic::closure$0<ref$<str$> >()|git:github.com/rust-lang/rust:library/std/src/panicking.rs:4d91de4e48198da2e33413efdcd9cd2cc0c46688|765|0x2c
0|5|xul.dll|std::sys::backtrace::__rust_end_short_backtrace<std::panicking::begin_panic::closure_env$0<ref$<str$> >,never$>()|git:github.com/rust-lang/rust:library/std/src/sys/backtrace.rs:4d91de4e48198da2e33413efdcd9cd2cc0c46688|168|0xe
0|6|xul.dll|std::panicking::begin_panic<ref$<str$> >()|git:github.com/rust-lang/rust:library/std/src/panicking.rs:4d91de4e48198da2e33413efdcd9cd2cc0c46688|764|0x20
0|7|xul.dll|style::custom_properties::do_substitute_chunk(ref$<str$>, unsigned long long, unsigned long long, cssparser::serializer::TokenSerializationType, cssparser::serializer::TokenSerializationType, style::stylesheets::UrlExtraData*, style::custom_properties::ComputedCustomProperties*, style::properties_and_values::registry::PropertyRegistrationData*, style::stylist::Stylist*, style::values::computed::Context*, core::iter::adapters::peekable::Peekable<core::slice::iter::Iter<style::custom_properties::VarOrEnvReference> >*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/custom_properties.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|2043|0xe05
0|8|xul.dll|style::custom_properties::substitute(style::custom_properties::VariableValue*, style::custom_properties::ComputedCustomProperties*, style::stylist::Stylist*, style::values::computed::Context*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/custom_properties.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|2184|0xbb
0|9|xul.dll|style::properties::UnparsedValue::substitute_variables(style::properties::generated::LonghandId, style::custom_properties::ComputedCustomProperties*, style::stylist::Stylist*, style::values::computed::Context*, std::collections::hash::map::HashMap<tuple$<style::properties::generated::ShorthandId,style::properties::generated::LonghandId>,enum2$<style::properties::generated::PropertyDeclaration>,core::hash::BuildHasherDefault<fxhash::FxHasher> >*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/properties/mod.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1418|0x241
0|10|xul.dll|style::properties::cascade::Cascade::apply_one_longhand(style::values::computed::Context*, style::properties::generated::LonghandId, enum2$<style::properties::generated::PropertyDeclaration>*, style::applicable_declarations::CascadePriority, std::collections::hash::map::HashMap<tuple$<style::properties::generated::ShorthandId,style::properties::generated::LonghandId>,enum2$<style::properties::generated::PropertyDeclaration>,core::hash::BuildHasherDefault<fxhash::FxHasher> >*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/properties/cascade.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|894|0x2cc
0|11|xul.dll|style::properties::cascade::Cascade::apply_non_prioritary_properties(style::values::computed::Context*, ref$<slice2$<style::properties::cascade::Declaration> >, std::collections::hash::map::HashMap<tuple$<style::properties::generated::ShorthandId,style::properties::generated::LonghandId>,enum2$<style::properties::generated::PropertyDeclaration>,core::hash::BuildHasherDefault<fxhash::FxHasher> >*, style::properties::LonghandIdSet*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/properties/cascade.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|850|0xa2
0|12|xul.dll|style::properties::cascade::cascade_rules<style::gecko::wrapper::GeckoElement>(style::stylist::Stylist*, enum2$<core::option::Option<ref$<enum2$<style::gecko::pseudo_element::PseudoElement> > > >, style::rule_tree::core::StrongRuleNode*, style::shared_lock::StylesheetGuards*, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<style::properties::cascade::FirstLineReparenting>, enum2$<style::properties::cascade::CascadeMode>, style::computed_value_flags::ComputedValueFlags, enum2$<core::option::Option<ref$<style::rule_cache::RuleCache> > >, style::rule_cache::RuleCacheConditions*, enum2$<core::option::Option<style::gecko::wrapper::GeckoElement> >)|hg:hg.mozilla.org/mozilla-central:servo/components/style/properties/cascade.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|198|0x7fb
0|13|xul.dll|style::style_resolver::StyleResolverForElement<style::gecko::wrapper::GeckoElement>::cascade_style_and_visited<style::gecko::wrapper::GeckoElement>(style::context::CascadeInputs, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<core::option::Option<ref$<enum2$<style::gecko::pseudo_element::PseudoElement> > > >)|hg:hg.mozilla.org/mozilla-central:servo/components/style/style_resolver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|382|0x126
0|14|xul.dll|style::style_resolver::StyleResolverForElement<style::gecko::wrapper::GeckoElement>::cascade_primary_style<style::gecko::wrapper::GeckoElement>(style::context::CascadeInputs, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, selectors::context::IncludeStartingStyle, bool)|hg:hg.mozilla.org/mozilla-central:servo/components/style/style_resolver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|277|0x3e4
0|15|xul.dll|style::style_resolver::impl$4::cascade_styles_with_default_parents::closure$0<style::gecko::wrapper::GeckoElement>(style::style_resolver::impl$4::cascade_styles_with_default_parents::closure_env$0<style::gecko::wrapper::GeckoElement>, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >, enum2$<core::option::Option<ref$<style::properties::generated::gecko::ComputedValues> > >)|hg:hg.mozilla.org/mozilla-central:servo/components/style/style_resolver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|411|0x6e
0|16|xul.dll|style::style_resolver::StyleResolverForElement<style::gecko::wrapper::GeckoElement>::cascade_styles_with_default_parents<style::gecko::wrapper::GeckoElement>(style::context::ElementCascadeInputs, bool)|hg:hg.mozilla.org/mozilla-central:servo/components/style/style_resolver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|410|0x10f
0|17|xul.dll|style::traversal::compute_style<style::gecko::wrapper::GeckoElement>(style::traversal::PerLevelTraversalData*, style::context::StyleContext<style::gecko::wrapper::GeckoElement>*, style::gecko::wrapper::GeckoElement, style::data::ElementData*, enum2$<style::data::RestyleKind>)|hg:hg.mozilla.org/mozilla-central:servo/components/style/traversal.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|646|0x1ec
0|18|xul.dll|style::parallel::style_trees<style::gecko::wrapper::GeckoElement,style::gecko::traversal::RecalcStyleOnly>(style::context::StyleContext<style::gecko::wrapper::GeckoElement>*, alloc::collections::vec_deque::VecDeque<style::dom::SendNode<style::gecko::wrapper::GeckoNode>,alloc::alloc::Global>, style_traits::dom::OpaqueNode, unsigned long long, style::traversal::PerLevelTraversalData, enum2$<core::option::Option<ref$<rayon_core::scope::ScopeFifo> > >, style::gecko::traversal::RecalcStyleOnly*, style::scoped_tls::ScopedTLS<style::context::ThreadLocalStyleContext<style::gecko::wrapper::GeckoElement> >*)|hg:hg.mozilla.org/mozilla-central:servo/components/style/parallel.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|158|0x306
0|19|xul.dll|style::driver::traverse_dom::closure$0<style::gecko::wrapper::GeckoElement,style::gecko::traversal::RecalcStyleOnly>(style::driver::traverse_dom::closure_env$0<style::gecko::wrapper::GeckoElement,style::gecko::traversal::RecalcStyleOnly>, enum2$<core::option::Option<ref$<rayon_core::scope::ScopeFifo> > >)|hg:hg.mozilla.org/mozilla-central:servo/components/style/driver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|138|0x230
0|20|xul.dll|style::driver::traverse_dom<style::gecko::wrapper::GeckoElement,style::gecko::traversal::RecalcStyleOnly>(style::gecko::traversal::RecalcStyleOnly*, style::traversal::PreTraverseToken<style::gecko::wrapper::GeckoElement>, enum2$<core::option::Option<ref$<rayon_core::thread_pool::ThreadPool> > >)|hg:hg.mozilla.org/mozilla-central:servo/components/style/driver.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|127|0x212
0|21|xul.dll|geckoservo::glue::traverse_subtree(style::gecko::wrapper::GeckoElement, style::global_style_data::GlobalStyleData*, style::gecko::data::PerDocumentStyleDataImpl*, style::shared_lock::SharedRwLockReadGuard*, style::traversal_flags::TraversalFlags, style::gecko_bindings::structs::root::mozilla::ServoElementSnapshotTable*)|hg:hg.mozilla.org/mozilla-central:servo/ports/geckolib/glue.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|316|0x365
0|22|xul.dll|geckoservo::glue::Servo_TraverseSubtree(style::gecko_bindings::structs::root::mozilla::dom::Element*, style::gecko::data::PerDocumentStyleData*, style::gecko_bindings::structs::root::mozilla::ServoElementSnapshotTable*, unsigned int)|hg:hg.mozilla.org/mozilla-central:servo/ports/geckolib/glue.rs:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|366|0x290
0|23|xul.dll|mozilla::ServoStyleSet::StyleDocument(mozilla::ServoTraversalFlags)|hg:hg.mozilla.org/mozilla-central:layout/style/ServoStyleSet.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|828|0x254
0|24|xul.dll|mozilla::RestyleManager::DoProcessPendingRestyles(mozilla::ServoTraversalFlags)|hg:hg.mozilla.org/mozilla-central:layout/base/RestyleManager.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|3270|0x1ba
0|25|xul.dll|mozilla::RestyleManager::ProcessPendingRestyles()|hg:hg.mozilla.org/mozilla-central:layout/base/RestyleManager.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|3405|0x73
0|26|xul.dll|mozilla::PresShell::DoFlushPendingNotifications(mozilla::ChangesToFlush)|hg:hg.mozilla.org/mozilla-central:layout/base/PresShell.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|4568|0x652
0|27|xul.dll|nsRefreshDriver::FlushLayoutOnPendingDocsAndFixUpFocus()|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|2203|0x26a
0|28|xul.dll|nsRefreshDriver::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsRefreshDriver::IsExtraTick)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|2784|0xb18
0|29|xul.dll|mozilla::RefreshDriverTimer::TickRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|346|0xb4
0|30|xul.dll|mozilla::RefreshDriverTimer::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|362|0xbb
0|31|xul.dll|mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|948|0x32
0|32|xul.dll|mozilla::VsyncRefreshDriverTimer::TickRefreshDriver(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|858|0x214
0|33|xul.dll|mozilla::VsyncRefreshDriverTimer::NotifyVsyncOnMainThread(mozilla::VsyncEvent const&)|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|759|0x44b
0|34|xul.dll|mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsyncTimerOnMainThread()|hg:hg.mozilla.org/mozilla-central:layout/base/nsRefreshDriver.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|593|0xd8
0|35|xul.dll|mozilla::dom::VsyncMainChild::RecvNotify(mozilla::VsyncEvent const&, float const&)|hg:hg.mozilla.org/mozilla-central:dom/ipc/VsyncMainChild.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|66|0xf1
0|36|xul.dll|mozilla::dom::PVsyncChild::OnMessageReceived(IPC::Message const&)|s3:gecko-generated-sources:892867c967752e8572b3c48e1e8ec5542612cadef83ec8d26f81a66342272c6d6d51cb22d80c9e6867472cb07ff431977f3f9d04f971f91004e7058c76c20573/ipc/ipdl/PVsyncChild.cpp:|235|0x277
0|37|xul.dll|mozilla::ipc::PBackgroundChild::OnMessageReceived(IPC::Message const&)|s3:gecko-generated-sources:29b36c066f5e2e5450eac0bfad0ff765f6a1309e11ea958a308e7f0df8e5308cb70723e31e322172c08b1dc9e456db80236106afd27eac0aab4f4df2132b7d67/ipc/ipdl/PBackgroundChild.cpp:|5178|0x19d
0|38|xul.dll|mozilla::ipc::MessageChannel::DispatchAsyncMessage(mozilla::ipc::ActorLifecycleProxy*, IPC::Message const&)|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessageChannel.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1789|0x14c
0|39|xul.dll|mozilla::ipc::MessageChannel::DispatchMessage(mozilla::ipc::ActorLifecycleProxy*, mozilla::UniquePtr<IPC::Message,mozilla::DefaultDelete<IPC::Message> >)|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessageChannel.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1716|0x255
0|40|xul.dll|mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::ActorLifecycleProxy*, mozilla::ipc::MessageChannel::MessageTask&)|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessageChannel.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1507|0x193
0|41|xul.dll|mozilla::ipc::MessageChannel::MessageTask::Run()|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessageChannel.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1607|0xdd
0|42|xul.dll|mozilla::RunnableTask::Run()|hg:hg.mozilla.org/mozilla-central:xpcom/threads/TaskController.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|703|0x1d
0|43|xul.dll|mozilla::TaskController::DoExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex &> const&)|hg:hg.mozilla.org/mozilla-central:xpcom/threads/TaskController.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1250|0x737
0|44|xul.dll|mozilla::TaskController::ExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex &> const&)|hg:hg.mozilla.org/mozilla-central:xpcom/threads/TaskController.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1073|0x57
0|45|xul.dll|mozilla::TaskController::ProcessPendingMTTask(bool)|hg:hg.mozilla.org/mozilla-central:xpcom/threads/TaskController.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|639|0x69
0|46|xul.dll|mozilla::detail::RunnableFunction<`lambda at /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:333:7'>::Run()|hg:hg.mozilla.org/mozilla-central:xpcom/threads/nsThreadUtils.h:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|548|0x16
0|47|xul.dll|nsThread::ProcessNextEvent(bool, bool*)|hg:hg.mozilla.org/mozilla-central:xpcom/threads/nsThread.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|1159|0x66b
0|48|xul.dll|NS_ProcessNextEvent(nsIThread*, bool)|hg:hg.mozilla.org/mozilla-central:xpcom/threads/nsThreadUtils.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|480|0x70
0|49|xul.dll|mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*)|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessagePump.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|85|0xb7
0|50|xul.dll|MessageLoop::RunHandler()|hg:hg.mozilla.org/mozilla-central:ipc/chromium/src/base/message_loop.cc:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|362|0x3e
0|51|xul.dll|MessageLoop::Run()|hg:hg.mozilla.org/mozilla-central:ipc/chromium/src/base/message_loop.cc:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|344|0x6e
0|52|xul.dll|nsBaseAppShell::Run()|hg:hg.mozilla.org/mozilla-central:widget/nsBaseAppShell.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|148|0x27
0|53|xul.dll|nsAppShell::Run()|hg:hg.mozilla.org/mozilla-central:widget/windows/nsAppShell.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|688|0x193
0|54|xul.dll|XRE_RunAppShell()|hg:hg.mozilla.org/mozilla-central:toolkit/xre/nsEmbedFunctions.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|646|0x78
0|55|xul.dll|mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*)|hg:hg.mozilla.org/mozilla-central:ipc/glue/MessagePump.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|235|0x39
0|56|xul.dll|MessageLoop::RunHandler()|hg:hg.mozilla.org/mozilla-central:ipc/chromium/src/base/message_loop.cc:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|362|0x3e
0|57|xul.dll|MessageLoop::Run()|hg:hg.mozilla.org/mozilla-central:ipc/chromium/src/base/message_loop.cc:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|344|0x6e
0|58|xul.dll|XRE_InitChildProcess(int, char**, XREChildData const*)|hg:hg.mozilla.org/mozilla-central:toolkit/xre/nsEmbedFunctions.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|584|0x97c
0|59|firefox.exe|NS_internal_main(int, char**, char**)|hg:hg.mozilla.org/mozilla-central:browser/app/nsBrowserApp.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|397|0x1fd
0|60|firefox.exe|wmain(int, wchar_t**)|hg:hg.mozilla.org/mozilla-central:toolkit/xre/nsWindowsWMain.cpp:2879c26ed4ccd7a9b005c95872bbf91bde6dc001|151|0x246

Comment 1

[Daniel Holbert [:dholbert]]

This seems to be a debug-only assert:
https://searchfox.org/mozilla-central/rev/5c2888b35d56928d252acf84e8816fa89a8a6a61/servo/components/style/custom_properties.rs#2061

debug_assert!(v.is_parsed(registration), "Should be already computed");

...and I'm not immediately seeing a crash when I visit the site with a regular Nightly, so I'm assuming/hoping this doesn't cause much observable trouble for users. Hence, triaging as S3.

(emilio, would you mind double-checking me on that -- i.e. is this assertion particularly concern-worthy -- and maybe see if a quick look at the pernosco trace has any clues about what's gone wrong?)

Comment 2

[Daniel Holbert [:dholbert]]

(adding dependency on the bug that added this assertion, which is bug 1877383, though I don't know offhand whether this failure was reproducible at that point vs. if there's something that's changed more recently that made the assertion start failing.)

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Yeah this crash is harmless in release. In fact I think that we have one test which hits that assert right now (css/css-variables/variable-css-wide-keywords.html).