Volume subpath silently fails

services:
    foo:
        image: ubuntu
        volumes:
            - type: volume
              source: bar
              volume: { subpath: baz }
              target: /baz

From https://github.com/moby/swarmkit/blob/master/swarmd/dockerexec/container.go#L338-L343:

if m.VolumeOptions != nil {
	mount.VolumeOptions = &enginemount.VolumeOptions{
		NoCopy: m.VolumeOptions.NoCopy,
		// TODO: uncomment after 26.0 vendor
		// Subpath: m.VolumeOptions.Subpath,
	}

Has Docker 26.0 been vendored? If so, please enable volume subpath support! If not, please emit an error message.

Start by checking the Docker engine dependency and vendored version, then inspect swarmd/dockerexec/container.go around lines 338-343. Confirm whether the available mount API includes volume subpath support; done means the subpath is forwarded or the configuration produces an explicit error instead of silently failing.