Panic on wikipedia page

[jdm]

Loading https://en.wikipedia.org/wiki/Section_20A in layout-2020 panics:

called `Option::unwrap()` on a `None` value (thread StyleThread#1, at /Users/joshmatthews/src/servo-tmp/components/layout_2020/dom_traversal.rs:451)
   0: backtrace::backtrace::trace_unsynchronized
   1: <servo::backtrace::Print as core::fmt::Debug>::fmt
   2: core::fmt::write
   3: std::io::Write::write_fmt
   4: servo::backtrace::print
   5: servo::main::{{closure}}
   6: std::panicking::rust_panic_with_hook
   7: rust_begin_unwind
   8: core::panicking::panic_fmt
   9: core::panicking::panic
  10: core::option::Option<T>::unwrap
  11: <T as layout::dom_traversal::NodeExt>::layout_data_mut
  12: <T as layout::dom_traversal::NodeExt>::unset_boxes_in_subtree
  13: layout::dom_traversal::traverse_element
  14: layout::dom_traversal::traverse_children_of
  15: layout::dom_traversal::NonReplacedContents::traverse
  16: layout::flow::construct::<impl layout::flow::BlockContainer>::construct
  17: layout::flow::construct::IntermediateBlockContainer::finish
  18: layout::flow::construct::BlockLevelJob<Node>::finish
  19: layout::flow::construct::<impl layout::flow::BlockContainer>::construct::{{closure}}
  20: <rayon_croissant::consumer::MapfoldReduceFolder<Accumulator,Mapfold,OutputConsumer> as rayon::iter::plumbing::Folder<Input>>::consume
  21: rayon::iter::plumbing::Folder::consume_iter
  22: rayon::iter::plumbing::Producer::fold_with
  23: rayon::iter::plumbing::bridge_producer_consumer::helper
  24: rayon::iter::plumbing::bridge_producer_consumer::helper::{{closure}}
  25: rayon_core::join::join_context::call_b::{{closure}}
  26: rayon_core::job::StackJob<L,F,R>::run_inline
  27: rayon_core::join::join_context::{{closure}}
  28: rayon_core::registry::in_worker
  29: rayon_core::join::join_context
  30: rayon::iter::plumbing::bridge_producer_consumer::helper
  31: rayon::iter::plumbing::bridge_producer_consumer::helper::{{closure}}
  32: rayon_core::join::join_context::call_b::{{closure}}
  33: rayon_core::job::StackJob<L,F,R>::run_inline
  34: rayon_core::join::join_context::{{closure}}
  35: rayon_core::registry::in_worker
  36: rayon_core::join::join_context
  37: rayon::iter::plumbing::bridge_producer_consumer::helper
  38: rayon::iter::plumbing::bridge_producer_consumer
  39: <rayon::iter::plumbing::bridge::Callback<C> as rayon::iter::plumbing::ProducerCallback<I>>::callback
  40: <rayon::vec::IntoIter<T> as rayon::iter::IndexedParallelIterator>::with_producer
  41: rayon::iter::plumbing::bridge
  42: <rayon::vec::IntoIter<T> as rayon::iter::ParallelIterator>::drive_unindexed
  43: <rayon_croissant::MapfoldReduce<Accumulator,Input,Mapfold,Init,Reduce> as rayon::iter::ParallelIterator>::drive_unindexed
  44: rayon::iter::collect::special_extend
  45: rayon::iter::collect::<impl rayon::iter::ParallelExtend<T> for alloc::vec::Vec<T>>::par_extend
  46: rayon::iter::from_par_iter::collect_extended
  47: rayon::iter::from_par_iter::<impl rayon::iter::FromParallelIterator<T> for alloc::vec::Vec<T>>::from_par_iter
  48: rayon::iter::ParallelIterator::collect
  49: layout::flow::construct::<impl layout::flow::BlockContainer>::construct
  50: layout::flow::construct::IntermediateBlockContainer::finish
  51: layout::flow::construct::BlockLevelJob<Node>::finish
  52: layout::flow::construct::<impl layout::flow::BlockContainer>::construct::{{closure}}
  53: <rayon_croissant::consumer::MapfoldReduceFolder<Accumulator,Mapfold,OutputConsumer> as rayon::iter::plumbing::Folder<Input>>::consume
  54: rayon::iter::plumbing::Folder::consume_iter
  55: rayon::iter::plumbing::Producer::fold_with
  56: rayon::iter::plumbing::bridge_producer_consumer::helper
  57: rayon::iter::plumbing::bridge_producer_consumer::helper::{{closure}}
  58: rayon_core::join::join_context::call_b::{{closure}}
  59: rayon_core::job::StackJob<L,F,R>::run_inline
  60: rayon_core::join::join_context::{{closure}}
  61: rayon_core::registry::in_worker
  62: rayon_core::join::join_context
  63: rayon::iter::plumbing::bridge_producer_consumer::helper
  64: rayon::iter::plumbing::bridge_producer_consumer::helper::{{closure}}
  65: rayon_core::join::join_context::call_a::{{closure}}
  66: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  67: std::panicking::try::do_call
  68: __rust_try
  69: std::panicking::try
  70: std::panic::catch_unwind
  71: rayon_core::unwind::halt_unwinding
  72: rayon_core::join::join_context::{{closure}}
  73: rayon_core::registry::in_worker
  74: rayon_core::join::join_context
  75: rayon::iter::plumbing::bridge_producer_consumer::helper
  76: rayon::iter::plumbing::bridge_producer_consumer
  77: <rayon::iter::plumbing::bridge::Callback<C> as rayon::iter::plumbing::ProducerCallback<I>>::callback
  78: <rayon::vec::IntoIter<T> as rayon::iter::IndexedParallelIterator>::with_producer
  79: rayon::iter::plumbing::bridge
  80: <rayon::vec::IntoIter<T> as rayon::iter::ParallelIterator>::drive_unindexed
  81: <rayon_croissant::MapfoldReduce<Accumulator,Input,Mapfold,Init,Reduce> as rayon::iter::ParallelIterator>::drive_unindexed
  82: rayon::iter::collect::special_extend
  83: rayon::iter::collect::<impl rayon::iter::ParallelExtend<T> for alloc::vec::Vec<T>>::par_extend
  84: rayon::iter::from_par_iter::collect_extended
  85: rayon::iter::from_par_iter::<impl rayon::iter::FromParallelIterator<T> for alloc::vec::Vec<T>>::from_par_iter
  86: rayon::iter::ParallelIterator::collect
  87: layout::flow::construct::<impl layout::flow::BlockContainer>::construct
  88: layout::flow::construct::IntermediateBlockContainer::finish
  89: layout::flow::construct::BlockLevelJob<Node>::finish
  90: layout::flow::construct::<impl layout::flow::BlockContainer>::construct::{{closure}}
  91: <rayon_croissant::consumer::MapfoldReduceFolder<Accumulator,Mapfold,OutputConsumer> as rayon::iter::plumbing::Folder<Input>>::consume
  92: rayon::iter::plumbing::Folder::consume_iter
  93: rayon::iter::plumbing::Producer::fold_with
  94: rayon::iter::plumbing::bridge_producer_consumer::helper
  95: rayon::iter::plumbing::bridge_producer_consumer
  96: <rayon::iter::plumbing::bridge::Callback<C> as rayon::iter::plumbing::ProducerCallback<I>>::callback
  97: <rayon::vec::IntoIter<T> as rayon::iter::IndexedParallelIterator>::with_producer
  98: rayon::iter::plumbing::bridge
  99: <rayon::vec::IntoIter<T> as rayon::iter::ParallelIterator>::drive_unindexed
 100: <rayon_croissant::MapfoldReduce<Accumulator,Input,Mapfold,Init,Reduce> as rayon::iter::ParallelIterator>::drive_unindexed
 101: rayon::iter::collect::special_extend
 102: rayon::iter::collect::<impl rayon::iter::ParallelExtend<T> for alloc::vec::Vec<T>>::par_extend
 103: rayon::iter::from_par_iter::collect_extended
 104: rayon::iter::from_par_iter::<impl rayon::iter::FromParallelIterator<T> for alloc::vec::Vec<T>>::from_par_iter
 105: rayon::iter::ParallelIterator::collect
 106: layout::flow::construct::<impl layout::flow::BlockContainer>::construct
 107: layout::flow::construct::<impl layout::flow::BlockFormattingContext>::construct
 108: layout::formatting_contexts::IndependentFormattingContext::construct
 109: layout::flow::root::construct_for_root_element
 110: layout::flow::root::BoxTreeRoot::construct
 111: layout_thread::LayoutThread::handle_reflow::{{closure}}
 112: core::ops::function::FnOnce::call_once
 113: rayon_core::thread_pool::ThreadPool::install::{{closure}}
 114: rayon_core::registry::Registry::in_worker_cold::{{closure}}::{{closure}}
 115: <rayon_core::job::StackJob<L,F,R> as rayon_core::job::Job>::execute::call::{{closure}}
 116: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
 117: std::panicking::try::do_call
 118: __rust_try
 119: std::panicking::try
 120: std::panic::catch_unwind
 121: rayon_core::unwind::halt_unwinding
 122: <rayon_core::job::StackJob<L,F,R> as rayon_core::job::Job>::execute
 123: rayon_core::job::JobRef::execute
 124: rayon_core::registry::WorkerThread::execute
 125: rayon_core::registry::WorkerThread::wait_until_cold
 126: rayon_core::registry::WorkerThread::wait_until
 127: rayon_core::registry::main_loop
 128: rayon_core::registry::ThreadBuilder::run
 129: <rayon_core::registry::DefaultSpawn as rayon_core::registry::ThreadSpawn>::spawn::{{closure}}
 130: std::sys_common::backtrace::__rust_begin_short_backtrace
 131: std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}
 132: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
 133: std::panicking::try::do_call
 134: __rust_try
 135: std::panicking::try
 136: std::panic::catch_unwind
 137: std::thread::Builder::spawn_unchecked::{{closure}}
 138: core::ops::function::FnOnce::call_once{{vtable.shim}}
 139: <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once
 140: std::sys::unix::thread::Thread::new::thread_start
 141: _pthread_start

This looks the immediate panic would be fixed by a commit in #26414.