Workaround.ps1

configuration FeatureNetCore 
{ 
    Import-DscResource -ModuleName PSDesiredStateConfiguration;

    Node localhost 
    { 
        File DestinationFolder 
        { 
            Ensure = "Present" 
            DestinationPath = $Node.Destination 
            Type = 'Directory' 
            Force = $true 
            PsDscRunAsCredential = [PSCredential]::New("USERNAME", ("SUPERNICEPASSWORD" | ConvertTo-SecureString -AsPlainText -Force)) 
        } 
    } 
}

configuration xScriptTest 
{ 
    Import-DscResource -ModuleName xPSDesiredStateConfiguration;

    Node localhost 
    { 
        xScript Test 
        { 
            GetScript = {@{}} 
            SetScript = {} 
            TestScript = {return $true} 
            PsDscRunAsCredential = [PSCredential]::New("USERNAME", ("SUPERNICEPASSWORD" | ConvertTo-SecureString -AsPlainText -Force)) 
        } 
    } 
}

configuration Nest 
{ 
    FeatureNetCore FeatureNetCore {} 
    xScriptTest xScriptTest {} 
}

$data = @{ 
    AllNodes = @( 
        @{ 
            NodeName = "localhost" 
            PsDscAllowPlainTextPassword = $true 
        } 
    ) 
}

Nest -ConfigurationData $data 
cat .\Nest\localhost.mof