There is a possible disk failure of our main CI host, 'gallium'. It is being investigated at: https://phabricator.wikimedia.org/T137265
We are very sorry for the inconvenience.
Major updates will be sent to the lists with minor updates/investigation on the task linked above.
Thanks to Kunal and Yuvi for responding so far.
Greg
wikitech-l@lists.wikimedia.org