Fixed: a worker's per-job credential could be written to the server logs.
Each build gets its own short-lived key that the worker uses to report progress
back to NixCI. When a request carrying that key failed, the whole request was
written to the server logs to help diagnose it, and the key went with it.
The keys involved were scoped to a single build and are no longer valid. Server
logs are kept for 15 days and are not public. Nothing else was affected, and no
action is needed on your side.
Request headers written to the logs are now filtered against the same list that
already covered cookies and login tokens, on requests NixCI sends as well as
the ones it receives.