Comment 1 for bug 1156932

If using nova's security group implemention you can not create security groups that overlap in name though quantum allows this. Periously nova would let you delete security groups if they overlapped in name as the admin user but this was dangerious as you didn't know which group you were deleting. That said the issue you are seeing is actually a python-novaclient issue -- it does not explose a way to delete via id. You can retreieve the security group ids by running:

nova --debug secgroup-list ;

Then you can make a curl call in order to delete the security group id that you want if it overlapps with another security group (for example: curl -i http://10.34.95.210:8774/v2/38025118215c4802adb4381f54d91535/os-security-groups/8516db07-9902-4e14-9cef-800fa9df4799 -X DELETE ..<snip>)

Or you could use the python-quantumclient which supports deleting security groups that overlap in name.