ko build with different KO_DOCKER_REPO but get different image format

[carlory]

(base) ➜  karpenter git:(main) ✗ KO_DOCKER_REPO="abc.local" ko build -B --push=false  sigs.k8s.io/karpenter/kwok
2025/01/26 18:14:13 Using base cgr.dev/chainguard/static:latest@sha256:853bfd4495abb4b65ede8fc9332513ca2626235589c2cef59b4fce5082d0836d for sigs.k8s.io/karpenter/kwok
2025/01/26 18:14:14 git is in a dirty state
Please check in your pipeline what can be changing the following files:
 M Makefile

2025/01/26 18:14:14 Building sigs.k8s.io/karpenter/kwok for linux/arm64
abc.local/kwok:latest@sha256:e01ee363f7007f73a4966469b6a5e7dfac32350c97bfab0085c2af648c529153
(base) ➜  karpenter git:(main) ✗ KO_DOCKER_REPO="kind.local" ko build -B --push=false  sigs.k8s.io/karpenter/kwok
2025/01/26 18:14:26 Using base cgr.dev/chainguard/static:latest@sha256:853bfd4495abb4b65ede8fc9332513ca2626235589c2cef59b4fce5082d0836d for sigs.k8s.io/karpenter/kwok
2025/01/26 18:14:27 git is in a dirty state
Please check in your pipeline what can be changing the following files:
 M Makefile

2025/01/26 18:14:27 Building sigs.k8s.io/karpenter/kwok for linux/arm64
2025/01/26 18:14:29 Loading kind.local/kwok:e01ee363f7007f73a4966469b6a5e7dfac32350c97bfab0085c2af648c529153
2025/01/26 18:14:31 Loaded kind.local/kwok:e01ee363f7007f73a4966469b6a5e7dfac32350c97bfab0085c2af648c529153
2025/01/26 18:14:31 Adding tag latest
2025/01/26 18:14:31 Added tag latest
kind.local/kwok:e01ee363f7007f73a4966469b6a5e7dfac32350c97bfab0085c2af648c529153

I build an image twice with different KO_DOCKER_REPO, but it prints different image formats. the second one uses digest as a tag. Is it a bug or expected behavior?

[carlory]

/cc @markusthoemmes