When defining the "Communities" as an org feature in a scratch definition file:

{

    "orgName": "my Project",

    "language" : "EN",    

    "features" : ["ExternalSharing", "AuthorApex", "Communities"],

    "edition": "Developer",

    "orgPreferences" : {

        "enabled": ["S1DesktopEnabled", "ChatterEnabled", "IsChatterProfileEnabled", "IsQuoteEnabled", "Translation"]

    }

}

I do get users with community licenses in a newly created scratch org, but the Communities feature is not enabled in it.

We do need it as we run a bunch of unit tests with Portal Users logic which fails on CI build due to Communities not being active.

Is there a way to solve it?