`$client` will be empty, you've probably meant `$module`. But compare to the existing behavior:

    $ Y2DIR=/var/lib/empty /sbin/yast2 frobnicator
    No such client module frobnicator
    The search path follows. It does not include the current directory.
      /y2update/clients
      /var/lib/empty/clients
      /home/mvidner/.yast2/clients
      /usr/share/YaST2/clients

which was beacuse of [bnc#342213](https://bugzilla.novell.com/show_bug.cgi?id=342213)