- Wait until the upload progress reaches 100% before clicking publish. The
browser-based upload only progresses while the page is open, so publishing
(and closing the browser) mid-upload cut it off and left the video stuck
partway (e.g. 76%).
- Add optional YT_PROXY (conf.py): where youtube.com is blocked, direct
connections time out and the chromium does not use the system proxy, so
allow pointing it at a local proxy explicitly.