How do I delete clock groups (created via set_clock_groups)

Hi,

I have been using set_false_paths between clocks, and found out that it is better to use clock groups using set_clock_groups. Therefore, I updated my SDC files, but I now have a slight issue.

 I use RTL compiler to do some sanity checks of SDC prior to handoff. In pseudo code

read netlsit

for sdc in func1.sdc func2.sdc scan.sdc loop

   reset_design

    read_sdc

    timing lint, timing reports etc

     write_sdc -strict

 endloop

Previously, this has worked well, but it seems that clock_groups cannot be deleted. In the above, reset_design leaves the clock groups untouched, therefore my exported SDC files have clock groups for clocks that may not exist.

As an experiment, I also rm /design/my_design and reloaded - the clock groups were still not deleted !

Any ideas?

Thanks,

Steven