On latest master, with the following icecat package: icecat 68.2.0-guix0-preview3 out /gnu/store/zqzhirykpqhay8n768aqqg4xplrmpfwz-icecat-68.2.0-guix0-preview3
On the console (via <f12>) I find the following message on websites with embedded videos: The video on this page can’t be played. Your system may not have the required video codecs for: video/mp4; codecs="avc1.42E01E mp4a.40.2
