Process terminated with panic.

[rudyeeee]

The following panic has occurred. What is the reason?

Dec 28 01:16:00 cloud-worker2 stenographer[9936]: panic: runtime error: index out of range
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: goroutine 6 [running]:
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/thread.(*Thread).pruneOldestThreadFiles(0xc420089720)
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/thread/thread.go:229 +0x2ee
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/thread.(*Thread).cleanUpOnLowDiskSpace(0xc420089720)
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/thread/thread.go:206 +0x498
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/thread.(*Thread).SyncFiles(0xc420089720)
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/thread/thread.go:353 +0x52
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/env.(*Env).syncFiles(0xc42007f6c0)
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/env/env.go:260 +0x4f
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/env.(*Env).(github.com/google/stenographer/env.syncFiles)-fm()
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/env/env.go:131 +0x2a
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: github.com/google/stenographer/env.(*Env).callEvery(0xc42007f6c0, 0xc420010cb0, 0x37e11d600)
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/env/env.go:179 +0x8b
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: created by github.com/google/stenographer/env.New
Dec 28 01:16:00 cloud-worker2 stenographer[9936]: #011/root/work/src/github.com/google/stenographer/env/env.go:131 +0x3d1
Dec 28 01:16:00 cloud-worker2 systemd[1]: stenographer.service: Main process exited, code=exited, status=2/INVALIDARGUMENT