Termbox SSR was reported to be down on Mon Sep 30 2019 11:43:05 GMT+0200. Looking at the commit history it seems unlikely that it broke because of newly deployed code. It may have run out of disk space.
The service is deployed on a labs instance.
Docs: https://gerrit.wikimedia.org/r/plugins/gitiles/wikibase/termbox/+/refs/heads/master/infrastructure/README.md