assertion failed: ellipsis_fragments.len() == 1 (thread LayoutThread PipelineId { namespace_id: PipelineNamespaceId(0), index: PipelineIndex(3) }, at /Users/jdm/src/servo/components/layout/fragment.rs:772)
stack backtrace:
   0:        0x10f0c55b1 - backtrace::backtrace::trace::hf69d5756c40bafc7
   1:        0x10f0c5c58 - backtrace::capture::Backtrace::new::h92e5f83ad3bb233c
   2:        0x10ed5c4fc - servo::main::{{closure}}::hf6443ebf81e66199
   3:        0x114361273 - std::panicking::rust_panic_with_hook::h3e771863e3ed8403
   4:        0x10fec2573 - std::panicking::begin_panic::h94258923a88c8674
   5:        0x11003d35a - layout::fragment::Fragment::transform_into_ellipsis::h438ff44d3bf59d07
   6:        0x110056c58 - layout::inline::LineBreaker::push_fragment_to_line::hd83cfdc26114cb54
   7:        0x110057622 - layout::inline::LineBreaker::split_line_at_last_known_good_position::h0c67809371a9c3a9
   8:        0x1100554c8 - layout::inline::LineBreaker::reflow_fragment::h40ff0b65cb4f02a2
   9:        0x110052625 - layout::inline::LineBreaker::reflow_fragments::hf1ae70c705b24d94
  10:        0x110051f82 - layout::inline::LineBreaker::scan_for_lines::h9de4388d261c6025
  11:        0x11005c7cc - <layout::inline::InlineFlow as layout::flow::Flow>::assign_block_size::h5d58d839c7d217d8
  12:        0x11008ff8b - <layout::traversal::AssignBSizes<'a> as layout::flow::PostorderFlowTraversal>::process::h3477b9c360ab6b67
  13:        0x11006aea6 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  14:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  15:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  16:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  17:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  18:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  19:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  20:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  21:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  22:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  23:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  24:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  25:        0x11006ae84 - layout::sequential::traverse_flow_tree_preorder::doit::h9ef088d634ad02b3
  26:        0x11006ac75 - layout::sequential::traverse_flow_tree_preorder::h9f05d6a9353cbd7d
  27:        0x10fdca22a - layout_thread::LayoutThread::solve_constraints::h8dc9cd0782aa6e1f
  28:        0x10fdd2117 - layout_thread::LayoutThread::perform_post_style_recalc_layout_passes::{{closure}}::h7be30c3a18ebf344
  29:        0x10fb9df7f - profile_traits::time::profile::h6c261d3b1b8f3ed4
  30:        0x10fdd1a60 - layout_thread::LayoutThread::perform_post_style_recalc_layout_passes::h479b2d2e6dbf3969
  31:        0x10fdceb63 - layout_thread::LayoutThread::handle_reflow::h72f2ec2961f891a9
  32:        0x10fdc81bd - layout_thread::LayoutThread::handle_request_helper::{{closure}}::hc7d47ef9d243a171
  33:        0x10fb9cf4f - profile_traits::time::profile::h020b1a8ee21efe70
  34:        0x10fdc76d2 - layout_thread::LayoutThread::handle_request_helper::h5d54f483bb96d08d
  35:        0x10fdc63bf - layout_thread::LayoutThread::handle_request::h93b84d371f279dcd
  36:        0x10fdc5315 - layout_thread::LayoutThread::start::h9b0152470f35579a
  37:        0x10fdc171d - <layout_thread::LayoutThread as layout_traits::LayoutThreadFactory>::create::{{closure}}::{{closure}}::he99659b3fbde1add
  38:        0x10fb9c9dd - profile_traits::mem::ProfilerChan::run_with_memory_reporting::hda8d984d87c7a0a2
  39:        0x10fdc1de2 - <layout_thread::LayoutThread as layout_traits::LayoutThreadFactory>::create::{{closure}}::h1be44ea9032c35c8
  40:        0x10fd970bb - <std::panic::AssertUnwindSafe<F> as core::ops::FnOnce<()>>::call_once::h3bcd7ab5878ed8ee
  41:        0x10fc1a1af - std::panicking::try::do_call::ha8f59e88188b6f4c
  42:        0x11436214a - __rust_maybe_catch_panic
  43:        0x10fc19670 - std::panicking::try::hfcf4e4e0772d1f1c
  44:        0x10fc17375 - std::panic::catch_unwind::h75c6658c00c4d757
  45:        0x10fc18250 - std::thread::Builder::spawn::{{closure}}::ha2723455ecd04240
  46:        0x10fcaa669 - <F as alloc::boxed::FnBox<A>>::call_box::hc6c860102f3f90f1
  47:        0x1143601f4 - std::sys::imp::thread::Thread::new::thread_start::h5f22426d80277e16
  48:     0x7fff8e409898 - _pthread_body
  49:     0x7fff8e409729 - _pthread_start