▶ CRASH [expected TIMEOUT] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-3.html
  │ 
  │ _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
  │ 
  │ 
  │ 
  │ Failed to get browsing context info from constellation.: Io(Custom { kind: ConnectionReset, error: "No senders exist for this port." }) (thread ScriptThread PipelineId { namespace_id: PipelineNamespaceId(2), index: PipelineIndex(3) }, at src/libcore/result.rs:1084)
  │ stack backtrace:
  │    0: __ZN9backtrace9backtrace5trace17h6bd49c37c3e2a608E (0x1101fb94b)
  │    1: __ZN9backtrace7capture9Backtrace3new17h3ec5d87241e0727cE (0x1101fab37)
  │    2: __ZN5servo4main28_$u7b$$u7b$closure$u7d$$u7d$17h14212de9f0afcb9aE (0x10d3e790b)
  │    3: __ZN3std9panicking20rust_panic_with_hook17he24eb6798ad54c68E (0x110382131)
  │    4: __ZN3std9panicking18continue_panic_fmt17hc41eddc40bb93eb6E (0x110381b9c)
  │    5: _rust_begin_unwind (0x110381a98)
  │    6: __ZN4core9panicking9panic_fmt17h81801588e8006fa1E (0x1103a22ce)
  │    7: __ZN4core6result13unwrap_failed17h759b9cbabad88910E (0x1103a23a8)
  │    8: __ZN6script13script_thread12ScriptThread19remote_window_proxy17h3de40eb87ee4108bE (0x10e0e9da4)
  │    9: __ZN6script13script_thread12ScriptThread29handle_msg_from_constellation17h8e434629980b4985E (0x10e0daba0)
  │   10: __ZN6script13script_thread12ScriptThread11handle_msgs17h5b6b659e4ca9dbb0E.llvm.10939716038701058040 (0x10e0d8403)
  │   11: __ZN14profile_traits3mem12ProfilerChan25run_with_memory_reporting17h48b7134700a222b2E (0x10e200157)
  │   12: __ZN3std10sys_common9backtrace28__rust_begin_short_backtrace17ha272b551d3242811E (0x10e4ad19b)
  │   13: __ZN3std9panicking3try7do_call17h561450d5725b7ae3E.llvm.11483137713229271735 (0x10d97ba4a)
  │   14: ___rust_maybe_catch_panic (0x11038a4ce)
  │   15: __ZN4core3ops8function6FnOnce40call_once$u7b$$u7b$vtable.shim$u7d$$u7d$17h1f196fcb4a5d1f4dE (0x10dbb8d95)
  │   16: __ZN83_$LT$alloc..boxed..Box$LT$F$GT$$u20$as$u20$core..ops..function..FnOnce$LT$A$GT$$GT$9call_once17h98f1a88439d0719cE (0x11037185d)
  │   17: __ZN3std3sys4unix6thread6Thread3new12thread_start17ha6c5c29f3ce7787bE (0x1103899fd)
  │   18: __pthread_body (0x7fff5dd5a660)
  │   19: __pthread_start (0x7fff5dd5a50c)
  │ [2019-08-27T10:13:21Z ERROR servo] Failed to get browsing context info from constellation.: Io(Custom { kind: ConnectionReset, error: "No senders exist for this port." })
  └ Pipeline failed in hard-fail mode.  Crashing!