DB error when trying to delete a group referenced from a user account restriction

[tbar0970]

Configure a user account to be restricted to person group X
Then try to delete group X.
DB error ensues:

Request: Array
(
[view] => _edit_group
[groupid] => 88
[action] => delete
)

Array
(
[0] => Array
(
[function] => _handleError
[class] => System_Controller
[type] => ->
[args] => Array
(
[0] => 256
[1] => Database Error: _doQuery: [Error message: Could not execute statement]
[Last executed query: DELETE FROM person_group WHERE id='88']
[Native code: 1451]
[Native message: Cannot delete or update a parent row: a foreign key constraint fails (je_imagine.account_group_restriction, CONSTRAINT account_group_restriction_groupid FOREIGN KEY (groupid) REFERENCES _person_group (id))]

               [2] => /home/jethro/code/2.10.1/include/general.php
               [3] => 54
               [4] => [Object/Array]
           )

   )