GstPlayer crash on https://mozilla.com/firefox

[asajeffrey]

Running servo on https://mozilla.com/firefox produces:

** (servo:11858): WARNING **: GstPlayer: scaletempo element not available. Audio pitch will not be preserved during trick modes

(servo:11858): GStreamer-CRITICAL **: gst_element_get_bus: assertion 'GST_IS_ELEMENT (element)' failed

(servo:11858): GStreamer-CRITICAL **: gst_bus_create_watch: assertion 'GST_IS_BUS (bus)' failed

(servo:11858): GLib-CRITICAL **: g_source_set_callback: assertion 'source != NULL' failed
Stack trace
stack backtrace:
   0:     0x55ce4a517c7c - backtrace::backtrace::trace::h34a5004b5e0f1dc7
   1:     0x55ce4a516f12 - <backtrace::capture::Backtrace as core::default::Default>::default::hae829d87a5db9150
   2:     0x55ce4a516f88 - backtrace::capture::Backtrace::new::hcbbf9ea3df342ffc
   3:     0x55ce4883b04a - servo::install_crash_handler::handler::h30f7ca45a0085785
   4:     0x55ce4b0535ac - WasmFaultHandler
                        at /home/ajeffrey/.cargo/registry/src/github.com-1ecc6299db9ec823/mozjs_sys-0.61.2/mozjs/js/src/wasm/WasmSignalHandlers.cpp:1494
   5:     0x7f3e00a7238f - <unknown>
   6:     0x7f3e017eecc4 - g_source_attach
   7:     0x7f3e022d851c - gst_player_main
                        at ../subprojects/gst-plugins-bad/gst-libs/gst/player/gstplayer.c:2910
   8:     0x7f3e01817c54 - <unknown>
   9:     0x7f3e00a686b9 - start_thread
  10:     0x7f3dff30141c - clone
  11:                0x0 - <unknown>
Stack trace
stack backtrace:
   0:     0x55ce4a517c7c - backtrace::backtrace::trace::h34a5004b5e0f1dc7
   1:     0x55ce4a516f12 - <backtrace::capture::Backtrace as core::default::Default>::default::hae829d87a5db9150
   2:     0x55ce4a516f88 - backtrace::capture::Backtrace::new::hcbbf9ea3df342ffc
   3:     0x55ce4883b04a - servo::install_crash_handler::handler::h30f7ca45a0085785
   4:     0x55ce4b0535ac - WasmFaultHandler
                        at /home/ajeffrey/.cargo/registry/src/github.com-1ecc6299db9ec823/mozjs_sys-0.61.2/mozjs/js/src/wasm/WasmSignalHandlers.cpp:1494
   5:     0x7f3e00a7238f - <unknown>
   6:     0x55ce4883b0d2 - servo::install_crash_handler::handler::h30f7ca45a0085785
   7:     0x55ce4b0535ac - WasmFaultHandler
                        at /home/ajeffrey/.cargo/registry/src/github.com-1ecc6299db9ec823/mozjs_sys-0.61.2/mozjs/js/src/wasm/WasmSignalHandlers.cpp:1494
   8:     0x7f3e00a7238f - <unknown>
   9:     0x7f3e017eecc4 - g_source_attach
  10:     0x7f3e022d851c - gst_player_main
                        at ../subprojects/gst-plugins-bad/gst-libs/gst/player/gstplayer.c:2910
  11:     0x7f3e01817c54 - <unknown>
  12:     0x7f3e00a686b9 - start_thread
  13:     0x7f3dff30141c - clone
  14:                0x0 - <unknown>
Stack trace

[ferjm]

CC @sdroege @ceyusa

[sdroege]

The crash and everything comes from here: https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/blob/master/gst-libs/gst/player/gstplayer.c#L2917

There should probably be some more assertions in that code. In your case the problem seems to be that you simply don't have the playbin element available, see line 2898 a bit above. You need to at least gst-plugins-base properly installed in addition to gst-plugins-bad.

[jdm]

@asajeffrey Was this on Magic Leap in particular? I can't reproduce this in macOS.

[asajeffrey]

It was on Linux.

[atouchet]

The page crashes Servo for me in Windows 10.

[ferjm]

@asajeffrey @atouchet could you confirm that you don't have gst-plugins-base installed, please?

[ferjm]

servo/media#167 should help with this. At the very least, we should not crash when these elements are missing.

[asajeffrey]

I don't have gst-plugins-base installed.

[atouchet]

Does gst-plugins-base come with the GStreamer installer? If so I may have it installed.

[ferjm]

servo/media#167 was already merged and used in Servo.