In a Wayland session, clicking on a video object embedded in a PDF file
leads to a segmentation violation with the following messages in the
terminal:
---
(evince:17773): Gdk-WARNING **: 14:01:02.483:
../../../../../gdk/x11/gdkwindow-x11.c:5653 drawable is not a native X11
window

ERROR: Caught a segmentation fault while loading plugin file:
/usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstvaapi.so

Please either:
- remove it and restart.
- run with --gst-disable-segtrap --gst-disable-registry-fork and debug.
---

It seems that the linked gstreamer is attempting to draw via X11 instead
of Wayland protocols. The libgstvaapi.so comes from package
gstreamer1.0-vaapi with version 1.18.5-1.

A PDF file which illustrates the problem is available at
https://risk-engineering.org/emarsden/tmp/bug-embedded-video.pdf (464Kb).