Panic logging into bandcamp

[jdm]

[2020-02-11T16:27:00Z ERROR script::dom::bindings::error] Error at :0:0 SecurityError: The operation is insecure.
11:27:07.832:
executing invisible recaptcha (scrollTopBeforeExecute = 0)
assertion failed: `(left == right)`
  left: `2`,
 right: `1`: This runtime still has live children. (thread ScriptThread PipelineId { namespace_id: PipelineNamespaceId(2), index: PipelineIndex(3) }, at /Users/jdm/.cargo/git/checkouts/rust-mozjs-8611526964119dd6/9b0d063/src/rust.rs:410)
stack backtrace:
[2020-02-11T16:27:11Z ERROR script::dom::bindings::error] Error at :0:0 SecurityError: The operation is insecure.
   0: backtrace::backtrace::libunwind::trace
             at /Users/jdm/.cargo/git/checkouts/backtrace-rs-96ebaf1bcb788384/91a0aa4/src/backtrace/libunwind.rs:86
      backtrace::backtrace::trace_unsynchronized
             at /Users/jdm/.cargo/git/checkouts/backtrace-rs-96ebaf1bcb788384/91a0aa4/src/backtrace/mod.rs:66
   1: <servo::backtrace::Print as core::fmt::Debug>::fmt
             at ports/glutin/backtrace.rs:49
   2: core::fmt::write
             at src/libcore/fmt/mod.rs:1057
   3: std::io::Write::write_fmt
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/io/mod.rs:1426
   4: servo::backtrace::print
             at ports/glutin/backtrace.rs:17
   5: servo::main::{{closure}}
             at ports/glutin/main2.rs:152
   6: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:476
   7: rust_begin_unwind
             at src/libstd/panicking.rs:380
   8: std::thread::local::fast::Key<T>::try_initialize
   9: <mozjs::rust::Runtime as core::ops::drop::Drop>::drop
             at /Users/jdm/.cargo/git/checkouts/rust-mozjs-8611526964119dd6/9b0d063/src/rust.rs:410
  10: core::ptr::real_drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:184
  11: core::ptr::real_drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:184
  12: core::ptr::real_drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:184
  13: core::ptr::drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:174
      <alloc::rc::Rc<T> as core::ops::drop::Drop>::drop
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/liballoc/rc.rs:1102
  14: core::ptr::real_drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:184
  15: core::ptr::real_drop_in_place
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ptr/mod.rs:184
  16: <script::script_thread::ScriptThread as script_traits::ScriptThreadFactory>::create::{{closure}}
             at components/script/script_thread.rs:816
  17: std::sys_common::backtrace::__rust_begin_short_backtrace
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/sys_common/backtrace.rs:129
  18: std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/thread/mod.rs:475
  19: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/panic.rs:318
  20: std::panicking::try::do_call
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/panicking.rs:305
  21: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:86
  22: std::panicking::try
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/panicking.rs:281
  23: std::panic::catch_unwind
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/panic.rs:394
  24: std::thread::Builder::spawn_unchecked::{{closure}}
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libstd/thread/mod.rs:474
  25: core::ops::function::FnOnce::call_once{{vtable.shim}}
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/libcore/ops/function.rs:232
  26: <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/liballoc/boxed.rs:1015
  27: <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once
             at /rustc/3291ae33907f2a866ea6cea89113200555038d06/src/liballoc/boxed.rs:1015
      std::sys_common::thread::start_thread
             at src/libstd/sys_common/thread.rs:13
      std::sys::unix::thread::Thread::new::thread_start
             at src/libstd/sys/unix/thread.rs:80
  28: <unknown>
  29: <unknown>
[2020-02-11T16:27:13Z ERROR servo] assertion failed: `(left == right)`
  left: `2`,
 right: `1`: This runtime still has live children.

[jdm]

The SecurityError comes from some JS that does a property get on a cross-origin windowproxy (

servo/components/script/dom/windowproxy.rs

Line 1008 in 55058b2

throw_security_error(cx)

). Either that code is insufficiently lenient for expected properties, or the frame shouldn't actually be treated as cross-origin. The script in question is part of reCaptcha:
recaptcha.frame.Main.init("[\x22finput\x22,null,[\x22conf\x22,null,\x226Ld7hz4UAAAAANlndw60vAheGUwN0Mb-qeWD_LHr\x22,0,null,[\x22JS_BR\x22]\n,0.75]\n]\n");