▶ CRASH [expected OK] /IndexedDB/nested-cloning-small.any.html
  │
  │ The SC holder does not have any relevant objects (thread Script(1,1), at components/script/dom/bindings/structuredclone.rs:149)
  │    0: backtrace::backtrace::libunwind::trace
  │              at /Users/jdm/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/backtrace-0.3.75/src/backtrace/libunwind.rs:117:9
  │       backtrace::backtrace::trace_unsynchronized
  │              at /Users/jdm/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/backtrace-0.3.75/src/backtrace/mod.rs:66:14
  │    1: <servoshell::backtrace::Print as core::fmt::Debug>::fmt
  │              at /Users/jdm/src/alt-servo/ports/servoshell/backtrace.rs:65:13
  │    2: core::fmt::rt::Argument::fmt
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/core/src/fmt/rt.rs:173:76
  │       core::fmt::write
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/core/src/fmt/mod.rs:1465:25
  │    3: std::io::default_write_fmt
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/io/mod.rs:639:11
  │    4: std::io::Write::write_fmt
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/io/mod.rs:1954:13
  │    5: servoshell::backtrace::print
  │              at /Users/jdm/src/alt-servo/ports/servoshell/backtrace.rs:18:5
  │    6: servoshell::panic_hook::panic_hook
  │              at /Users/jdm/src/alt-servo/ports/servoshell/panic_hook.rs:40:17
  │    7: core::ops::function::Fn::call
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/ops/function.rs:79:5
  │    8: <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/alloc/src/boxed.rs:1980:9
  │       std::panicking::rust_panic_with_hook
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/std/src/panicking.rs:841:13
  │    9: std::panicking::begin_panic_handler::{{closure}}
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/std/src/panicking.rs:706:13
  │   10: std::sys::backtrace::__rust_end_short_backtrace
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/std/src/sys/backtrace.rs:168:18
  │   11: __rustc::rust_begin_unwind
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/std/src/panicking.rs:697:5
  │   12: core::panicking::panic_fmt
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/core/src/panicking.rs:75:14
  │   13: core::panicking::panic_display
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/core/src/panicking.rs:268:5
  │       core::option::expect_failed
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/core/src/option.rs:2081:5
  │   14: core::option::Option<T>::expect
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/option.rs:960:21
  │   15: script::dom::bindings::structuredclone::read_object
  │              at /Users/jdm/src/alt-servo/components/script/dom/bindings/structuredclone.rs:149:10
  │   16: script::dom::bindings::structuredclone::read_callback
  │              at /Users/jdm/src/alt-servo/components/script/dom/bindings/structuredclone.rs:221:24
  │   17: __ZN23JSStructuredCloneReader9startReadEN2JS13MutableHandleINS0_5ValueEEENS_20ShouldAtomizeStringsE
  │   18: __ZN23JSStructuredCloneReader15readObjectFieldEN2JS6HandleIP8JSObjectEENS1_INS0_5ValueEEE
  │   19: __ZN23JSStructuredCloneReader4readEN2JS13MutableHandleINS0_5ValueEEEm
  │   20: __Z19ReadStructuredCloneP9JSContextRK21JSStructuredCloneDataN2JS20StructuredCloneScopeENS4_13MutableHandleINS4_5ValueEEERKNS4_15CloneDataPolicyEPK26JSStructuredCloneCallbacksPv
  │   21: mozjs::rust::wrappers::JS_ReadStructuredClone
  │              at /Users/jdm/.cargo/git/checkouts/mozjs-dd2a25693c61d87d/e0a4ee4/mozjs/src/rust.rs:1228:51
  │   22: script::dom::bindings::structuredclone::read
  │              at /Users/jdm/src/alt-servo/components/script/dom/bindings/structuredclone.rs:717:22
  │   23: script::dom::idbrequest::RequestListener::handle_async_request_finished
  │              at /Users/jdm/src/alt-servo/components/script/dom/idbrequest.rs:122:24
  │   24: script::dom::idbrequest::IDBRequest::execute_async::{{closure}}::{{closure}}
  │              at /Users/jdm/src/alt-servo/components/script/dom/idbrequest.rs:298:39
  │   25: <script::dom::idbrequest::IDBRequest::execute_async::{{closure}}::request_callback<F> as script::task::TaskOnce>::run_once
  │              at /Users/jdm/src/alt-servo/components/script/task.rs:54:17
  │   26: <script::task::CancellableTask<T> as script::task::TaskOnce>::run_once
  │              at /Users/jdm/src/alt-servo/components/script/task.rs:155:24
  │   27: <T as script::task::TaskBox>::run_box
  │              at /Users/jdm/src/alt-servo/components/script/task.rs:106:14
  │   28: script::script_thread::ScriptThread::handle_msg_from_script
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:1975:22
  │   29: script::script_thread::ScriptThread::handle_msgs::{{closure}}
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:1478:65
  │   30: script::script_thread::ScriptThread::profile_event
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:1700:13
  │   31: script::script_thread::ScriptThread::handle_msgs
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:1469:32
  │   32: script::script_thread::ScriptThread::start
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:1033:20
  │   33: <script::script_thread::ScriptThread as layout_api::ScriptThreadFactory>::create::{{closure}}::{{closure}}
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:445:39
  │   34: profile_traits::mem::ProfilerChan::run_with_memory_reporting
  │              at /Users/jdm/src/alt-servo/components/shared/profile/mem.rs:131:9
  │   35: <script::script_thread::ScriptThread as layout_api::ScriptThreadFactory>::create::{{closure}}
  │              at /Users/jdm/src/alt-servo/components/script/script_thread.rs:443:40
  │   36: std::sys::backtrace::__rust_begin_short_backtrace
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/sys/backtrace.rs:152:18
  │   37: std::thread::Builder::spawn_unchecked_::{{closure}}::{{closure}}
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/thread/mod.rs:559:17
  │   38: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:272:9
  │   39: std::panicking::catch_unwind::do_call
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/panicking.rs:589:40
  │   40: ___rust_try
  │   41: std::panicking::catch_unwind
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/panicking.rs:552:19
  │       std::panic::catch_unwind
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/panic.rs:359:14
  │       std::thread::Builder::spawn_unchecked_::{{closure}}
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/std/src/thread/mod.rs:557:30
  │   42: core::ops::function::FnOnce::call_once{{vtable.shim}}
  │              at /Users/jdm/.rustup/toolchains/1.89.0-aarch64-apple-darwin/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
  │   43: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once
  │              at /rustc/29483883eed69d5fb4db01964cdf2af4d86e9cb2/library/alloc/src/boxed.rs:1966:9
  │       std::sys::pal::unix::thread::Thread::new::thread_start
  │              at /rustc/29483883eed69d