▶ CRASH [expected TIMEOUT] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_escaping-1.html
  │ 
  │ VMware, Inc.
  │ softpipe
  │ 3.3 (Core Profile) Mesa 18.3.0-devel
  │ Failed to get browsing context info from constellation.: Io(Custom { kind: ConnectionReset, error: StringError("All senders for this socket closed") }) (thread ScriptThread PipelineId { namespace_id: PipelineNamespaceId(2), index: PipelineIndex(3) }, at src/libcore/result.rs:999)
  │ stack backtrace:
  │    0:     0x7f8b62d03e5d - backtrace::backtrace::trace::h8cf5e823e7b927c4
  │    1:     0x7f8b62d02f42 - <backtrace::capture::Backtrace as core::default::Default>::default::hc91a77fe18f6f82e
  │    2:     0x7f8b607bf3e7 - servo::main::{{closure}}::h35768982dca81cb7
  │    3:     0x7f8b639ddb19 - std::panicking::rust_panic_with_hook::h3efc9269f3975b4e
  │                         at src/libstd/panicking.rs:482
  │    4:     0x7f8b639dd5c1 - std::panicking::continue_panic_fmt::h0bb834397df0d69a
  │                         at src/libstd/panicking.rs:385
  │    5:     0x7f8b639dd4a5 - rust_begin_unwind
  │                         at src/libstd/panicking.rs:312
  │    6:     0x7f8b639fd23c - core::panicking::panic_fmt::hce8ba5bc9a54c6f2
  │                         at src/libcore/panicking.rs:85
  │    7:     0x7f8b61391d4e - core::result::unwrap_failed::h9325188f0d97b600
  │    8:     0x7f8b61318360 - script::script_thread::ScriptThread::remote_window_proxy::h586ae72ffbd6f061
  │    9:     0x7f8b61308150 - script::script_thread::ScriptThread::handle_msg_from_constellation::h00b1d194fc128cea
  │   10:     0x7f8b61301f74 - _ZN6script13script_thread12ScriptThread11handle_msgs17h9e6b09790e3f4ea7E.llvm.3656274141805418547
  │   11:     0x7f8b612fced6 - script::script_thread::ScriptThread::start::h1484b91d67faaaad
  │   12:     0x7f8b61365f7e - profile_traits::mem::ProfilerChan::run_with_memory_reporting::ha803eda8ad327b82
  │   13:     0x7f8b61472de4 - std::sys_common::backtrace::__rust_begin_short_backtrace::h918092a582e94f30
  │   14:     0x7f8b619b8a85 - _ZN3std9panicking3try7do_call17h1e1a4a7559b185dcE.llvm.9973224621453256981
  │   15:     0x7f8b639e8829 - __rust_maybe_catch_panic
  │                         at src/libpanic_unwind/lib.rs:92
  │   16:     0x7f8b616da477 - <F as alloc::boxed::FnBox<A>>::call_box::hcc4b12433ee715fb
  │   17:     0x7f8b639e7bdd - <alloc::boxed::Box<(dyn alloc::boxed::FnBox<A, Output$u3d$R$GT$$u20$$u2b$$u20$$u27$a$RP$$GT$$u20$as$u20$core..ops..function..FnOnce$LT$A$GT$$GT$::call_once::hf75cbe88140b524c
  │                         at /rustc/c0bbc3927e28c22edefe6a1353b5ecc95ea9a104/src/liballoc/boxed.rs:734
  │                          - std::sys_common::thread::start_thread::h9fb334ae2abaae80
  │                         at src/libstd/sys_common/thread.rs:14
  │                          - std::sys::unix::thread::Thread::new::thread_start::h772c7ae2e9d50018
  │                         at src/libstd/sys/unix/thread.rs:81
  │   18:     0x7f8b5e409183 - start_thread
  │   19:     0x7f8b5ccd003c - clone
  │   20:                0x0 - <unknown>
  │ [2019-01-07T18:22:43Z ERROR servo] Failed to get browsing context info from constellation.: Io(Custom { kind: ConnectionReset, error: StringError("All senders for this socket closed") })
  └ Pipeline failed in hard-fail mode.  Crashing!