docker/cli · error

cannot push a digest reference

Error message

cannot push a digest reference

What it means

Error "cannot push a digest reference" thrown in docker/cli.

Source

Thrown at cmd/docker-trust/internal/trust/trust_push.go:75

		err := json.Unmarshal(*msg.Aux, &pushResult)
		if err == nil && pushResult.Tag != "" {
			if dgst, err := digest.Parse(pushResult.Digest); err == nil {
				h, err := hex.DecodeString(dgst.Hex())
				if err != nil {
					notaryTarget = nil
					return
				}
				notaryTarget.Name = pushResult.Tag
				notaryTarget.Hashes = data.Hashes{string(dgst.Algorithm()): h}
				notaryTarget.Length = int64(pushResult.Size)
			}
		}
	}

	var tag string
	switch x := ref.(type) {
	case reference.Digested:
		return errors.New("cannot push a digest reference")
	case reference.Tagged:
		tag = x.Tag()
	default:
		// We want trust signatures to always take an explicit tag,
		// otherwise it will act as an untrusted push.
		if err := jsonstream.Display(ctx, in, ioStreams.Out()); err != nil {
			return err
		}
		_, _ = fmt.Fprintln(ioStreams.Err(), "No tag specified, skipping trust metadata push")
		return nil
	}

	if err := jsonstream.Display(ctx, in, ioStreams.Out(), jsonstream.WithAuxCallback(handleTarget)); err != nil {
		return err
	}

	if cnt > 1 {
		return errors.New("internal error: only one call to handleTarget expected")

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cmd/docker-trust/internal/trust/trust_push.go:75 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/14f539a9311504a8.json. Report an issue: GitHub.