The following error was observed on 2021-02-02 11:15:

GitHub Activity Service: walkSegMail(github.fileSeg{file:"/2021-02.reclog", skip:0, size:4096}): truncated record at offset 0: EOF
Gerrit Activity Service: ok

Restarting fixed the issue.

It's looks like a possible race condition: the file length was determined to be 4096 bytes yet reading at offset 0 returned EOF. Maybe the file was still being written after being created, and the buffers weren't flushed?