if( -not $global:MyModulesWarning ) {
  $global:MyModulesWarning = @()
}
[MyConfig]::GetConfigPaths('mymodules',$false) |
    ForEach-Object {
        $( Get-Content $_ | ConvertFrom-Json ).Modules
    } | Where-Object {
        $local:m = $_
        if( $( try  {
            -not (Get-Module -ListAvailable $m -ErrorAction stop)
            } catch { $true }
        )) {
            $m -notin $global:MyModulesWarning
        }
    } | ForEach-Object {
        $global:MyModulesWarning += $_ 
        Write-Warning "Missing module: $_"
    }