Hello,
I have rolled back the deployment of 1.36.0-wmf.37 from all wikis since Special:Export was broken:
* Special:Export broken: always generates an empty file https://phabricator.wikimedia.org/T278579
The issue is reproducible on the beta cluster infrastructure and got spotted there last Friday: https://en.wikipedia.beta.wmflabs.org/wiki/Special:Export/Main_Page
Once the issue is resolve the train can resume.
If anyone has any lead as to why Special:Export might silently fail, any help is appreciated.
wmf.37 blocking task: https://phabricator.wikimedia.org/T278343
cheers,