called `Result::unwrap()` on an `Err` value: RecvError

[nukeador]

called Result::unwrap() on an Err value: RecvError

URL:

http://acid3.acidtests.org/

Backtrace:

frame #0  - 0x000055b1d81f3a0d - backtrace::backtrace::trace::hccde8df28b4db2a2
frame #1  - 0x000055b1d81f3995 - backtrace::capture::Backtrace::new::h42f95930bb8c5ee8
frame #2  - 0x000055b1d73c5379 - _<F as alloc..boxed..FnBox<A>>::call_box::hc555946005547ceb
frame #3  - 0x000055b1d81ea818 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::hc61828c8a9f6df01
frame #4  - 0x000055b1d82f1dcc - std::panicking::rust_panic_with_hook::h983af77c1a2e581b
frame #5  - 0x000055b1d830c3e1 - std::panicking::begin_panic::he426e15a3766089a
frame #6  - 0x000055b1d82f363a - std::panicking::begin_panic_fmt::hdddb415186c241e7
frame #7  - 0x000055b1d830c37e - rust_begin_unwind
frame #8  - 0x000055b1d834297f - core::panicking::panic_fmt::hf4e16cb7f0d41a25
frame #9  - 0x000055b1d739022d - core::result::unwrap_failed::h36b4b47aa6131a86
frame #10 - 0x000055b1d7398199 - script::dom::window::Window::new::hb019292f11913a6a
frame #11 - 0x000055b1d7443e67 - script::script_thread::ScriptThread::load::hba4290233876e7ff
frame #12 - 0x000055b1d72f58ee - script::script_thread::ScriptThread::page_headers_available::h9f01b6414ed029e2
frame #13 - 0x000055b1d72f0f83 - _<script..dom..servohtmlparser..ParserContext as net_traits..AsyncResponseListener>::headers_available::h557b607874eef3df
frame #14 - 0x000055b1d744a918 - _<script..network_listener..ListenerRunnable<A, Listener> as script..script_thread..Runnable>::handler::h4535b0ccca31f92f
frame #15 - 0x000055b1d73d02c4 - script::script_thread::ScriptThread::handle_msg_from_script::hfac8a5d67415fa31
frame #16 - 0x000055b1d742190f - script::script_thread::ScriptThread::handle_msgs::_$u7b$$u7b$closure$u7d$$u7d$::hcc3e5fcf08d42e0c
frame #17 - 0x000055b1d7408af7 - script::script_thread::ScriptThread::handle_msgs::hf9fbf9949e23273b
frame #18 - 0x000055b1d73c3a67 - std::panicking::try::call::h99112171a9854ab3
frame #19 - 0x000055b1d83165db - __rust_try
frame #20 - 0x000055b1d831657e - __rust_maybe_catch_panic
frame #21 - 0x000055b1d73c4cdd - _<F as alloc..boxed..FnBox<A>>::call_box::h4410a344b31b72da
frame #22 - 0x000055b1d830a5a4 - std::sys::thread::Thread::new::thread_start::h9c883b6d445ece46
frame #23 - 0x00007fc6227e66f9 - start_thread
frame #24 - 0x00007fc622306b5c - clone
frame #25 - 0x0000000000000000 - <unknown>

[jdm]

This is tracked by #6519. Thanks for reporting it!