Creating version, error (1) OmnistudioMetadata is not a valid Features value

First, it is a valid feature

according to the doc. 

Trying to build a package version that contains OmniStudio components (Transforms, Integration Procedures, Omni Scripts).   

here's the config/project-scratch-def.json

{
    "orgName": "My Package Org",
    "edition": "Enterprise",
    "features": [
        "OmniStudioDesigner",
        "OmniStudioMetadata",
        "OmniStudioRuntime"
    ],
    "settings": {
        "OmniStudioSettings": {
            "enableOmniStudioMetadata": true
        }
    }
}

And here's the packagedirectory entry

    {
      "versionName": "ver 0.1",
      "versionNumber": "0.1.0.NEXT",
      "path": "omnistudio",
      "default": true,
      "package": "Package Name",
      "versionDescription": "Package Description",
      "definitionFile": "config/project-scratch-def.json",
      "apexTestAccess": {
        "permissionSets": [
          "OmniStudioExecution"
        ]
      }
    }

Has anyone else gotten these errors and found the cause?