Intermittent timeout in /css/css-ui/text-overflow-025.html

[ferjm]

{"status": "TIMEOUT", "group": "default", "message": null, "stack": null, "subtest": null, "test": "/css/css-ui/text-overflow-025.html", "line": 28355, "action": "test_result", "expected": "FAIL"}

[jdm]

More specifically, the full output from the test was:

  ▶ TIMEOUT [expected FAIL] /css/css-ui/text-overflow-025.html
  │ 
  │ VMware, Inc.
  │ softpipe
  │ 3.3 (Core Profile) Mesa 18.3.0-devel
  │ Shutting down the Constellation after generating an output file or exit flag specified
  │ mozilla::detail::MutexImpl::lock: pthread_mutex_lock failed: Invalid argument
  │ VMware, Inc.
  │ softpipe
  │ 3.3 (Core Profile) Mesa 18.3.0-devel
  │ CloneApi message response was dropped while Webrender was still alive: io error: All senders for this socket closed (thread Constellation, at /home/servo/.cargo/git/checkouts/webrender-c3596abe1cf4f320/323b7ea/webrender_api/src/api.rs:952)
  │ stack backtrace:
  │    0:     0x7f79c4c0c3cc - backtrace::backtrace::trace::h8f3a081151eb58d3
  │    1:     0x7f79c4c0b5f2 - <backtrace::capture::Backtrace as core::default::Default>::default::h1f4987997aac7394
  │    2:     0x7f79c4c0b668 - backtrace::capture::Backtrace::new::hf2131665d3ac906b
  │    3:     0x7f79c2486729 - servo::main::{{closure}}::h988fddd992d28390
  │    4:     0x7f79c58bed13 - std::panicking::rust_panic_with_hook::hd470ff3b3e7a1b18
  │                         at libstd/panicking.rs:480
  │    5:     0x7f79c58be879 - std::panicking::continue_panic_fmt::hf0cf39ae1e114602
  │                         at libstd/panicking.rs:390
  │    6:     0x7f79c58be7dd - std::panicking::begin_panic_fmt::hfc5862442bd06bfc
  │                         at libstd/panicking.rs:345
  │    7:     0x7f79c4c3a6a0 - webrender_api::api::RenderApiSender::create_api::h761b84f54b5e33f9
  │    8:     0x7f79c259595d - constellation::pipeline::UnprivilegedPipelineContent::start_all::hd6cc2c31d120fd8a
  │    9:     0x7f79c25981b9 - constellation::pipeline::Pipeline::spawn::h48d67a3383f8705d
  │   10:     0x7f79c25c1b0b - <constellation::constellation::Constellation<Message, LTF, STF>>::new_pipeline::h3b14a4ca1793f7cd
  │   11:     0x7f79c25de344 - <constellation::constellation::Constellation<Message, LTF, STF>>::handle_request_from_compositor::h642c02e161e1022a
  │   12:     0x7f79c25e73d7 - <constellation::constellation::Constellation<Message, LTF, STF>>::run::h2b063e6902c45499
  │   13:     0x7f79c24d1d08 - std::sys_common::backtrace::__rust_begin_short_backtrace::h5518ccce68f67d93
  │   14:     0x7f79c25073b7 - _ZN3std9panicking3try7do_call17hebca6ef8cf171b60E.llvm.1637949047129989349
  │   15:     0x7f79c58d0f89 - __rust_maybe_catch_panic
  │                         at libpanic_unwind/lib.rs:102
  │   16:     0x7f79c24deb30 - <F as alloc::boxed::FnBox<A>>::call_box::hbf46745d25f36e44
  │   17:     0x7f79c58bbbfa - <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::h9d1cd498499ed135
  │                         at liballoc/boxed.rs:682
  │                          - std::sys_common::thread::start_thread::ha4bfe77455e6e434
  │                         at libstd/sys_common/thread.rs:24
  │   18:     0x7f79c58a87c5 - std::sys::unix::thread::Thread::new::thread_start::hebe133da3ea5230a
  │                         at libstd/sys/unix/thread.rs:90
  │   19:     0x7f79c00eb183 - start_thread
  │   20:     0x7f79be9b203c - clone
  │   21:                0x0 - <unknown>

This is another instance of #13480.