In CEL 1.16,

dyn([]).sum() == 0

This was always true

but in CEL 1.17, this sometimes returns false. It appears that this may be related to what type dyn([]) is assigned. If I run dyn([]).sum() it most often returns an int, but sometimes returns a uint or duration.

See https://github.com/kubernetes/kubernetes/blob/8a8d63a732dea705fd38fab7d79e3730642bb2f7/staging/src/k8s.io/apiserver/pkg/cel/library/lists.go#L139 for the sum() implementation.