Role0 -> Role1 -> Role2 -> Role3 -> ..... -> RoleN
At some value of N (depending on machine) seg fault will occur. It seems stack is blown, from many recursive calls to RoleGraph::_recomputePrivilegeDataHelper.
Role0 -> Role1 -> Role2 -> Role3 -> ..... -> RoleN -> Role0
Trying to create a large cycle (1600 roles) causes a segmentation fault. We think that the stack blew up (too many recursive calls to search through the role graph?). From the stack trace, it seems that 1396 calls to the RoleGraph::_recomputePrivilegeDataHelper went through before it blew the top.
Test that produced bugs is attached.