macOS nightlies can't play media (no such element factory "appsrc")

[jdm]

STR: visit http://dragonites.glitch.me/ in a nightly build

godot:MacOS jdm$ GST_DEBUG=2 ./servo http://dragonites.glitch.me/
A-Frame Version: 0.6.1 (Date 19-07-2017, Commit #a4b91bc)
three Version:
^0.84.0
WebVR Polyfill Version:
^0.9.36
Could not stop player Backend("Missing dependency: playbin")
Could not stop player Backend("Missing dependency: playbin")
[physics] `debug` cannot be changed dynamically.
[object Object]
%cpreset: goaland
color: #f48;font-weight:bold
%ccore:schema:warn %cUnknown property `color` for component/system `material`.%c
color: orange
color: inherit
color: orange
0:00:01.164200000 51993 0x7ffe0a765290 WARN     GST_ELEMENT_FACTORY gstelementfactory.c:456:GstElement *gst_element_factory_make(const gchar *, const gchar *): no such element factory "appsrc"!
Could not start audio render thread: Backend("appsrc creation failed") (thread AudioRenderThread, at src/libcore/result.rs:999)
[2019-06-05T16:29:40Z ERROR servo] Could not start audio render thread: Backend("appsrc creation failed")
called `Result::unwrap()` on an `Err` value: RecvError (thread ScriptThread PipelineId { namespace_id: PipelineNamespaceId(1), index: PipelineIndex(1) }, at src/libcore/result.rs:999)
[2019-06-05T16:29:41Z ERROR servo] called `Result::unwrap()` on an `Err` value: RecvError

[ferjm]

Missing dependency: playbin means that gst-plugins-base is not installed.

AFAICT we are not deploying GStreamer with Servo's OSX package.

[nicoabie]

@jdm It does play media now on MacOS 10.15.6!

[jdm]

Glad to know my efforts to fix media in macOS nightlies have not been in vain!