How to Create SPGroup without Permission Level using PowerShell

Question

How to create a SPGroup in my site collection with no permission level assigned using PowerShell. I have created the below script. But it fails to create SPGroup.

      foreach($groupName in $DisciplineGroups)
       {
        if ($mRootWeb.SiteGroups[$groupName] -ne $null)
         {
             Write-Host "Group "$($groupName)" already exists!"
             Break;
         }
       else
       {

        $mRootWeb.SiteGroups.Add($groupName, $mWeb.SiteUsers
         ["domain\myidd.dev"], $null, $description)  

        Write-Host " group  been created  
         on the root web $($mWeb.Title) with $($mWeb.url)"
          $group = $mRootWeb.SiteGroups[$groupName]

        $roleAssignment = new-object Microsoft.SharePoint.SPRoleAssignment
        ($group)

        #$roleDefinition = $web.Site.RootWeb.RoleDefinitions
         #[$permissionLevel]  

        $roleAssignment.RoleDefinitionBindings.Add($roleDefinition)  

        $mRootWeb.RoleAssignments.Add($roleAssignment) 

        $mRootWeb.Update()
       }  

or is this actually possible without a permission level?

Answer 1

At a glance, if you do not wish to add permissions to the group, don't!

Just do this part:

foreach($groupName in $DisciplineGroups)
{
    if ($mRootWeb.SiteGroups[$groupName] -ne $null)
    {
         Write-Host "Group "$($groupName)" already exists!"
         Break;
    }
    else
    {
        $mRootWeb.SiteGroups.Add($groupName, $mWeb.SiteUsers["domain\myidd.dev"], $null, $description)  
        Write-Host "Group  been created on the root web $($mWeb.Title) with $($mWeb.url)"
        $mRootWeb.Update()
    }
}