I could reproduce this issue with the MaintenanceTool provided by Qt5.1.0.
Steps to reproduce:
- start the MaintenanceTool.app
- check 'Package Manager'
- Continue but don't select or deselect something on the next pages
- when 'installation' is done - hit the 'Restart' button
- check 'Package Manager' again
- Segmentation fault
- no crash
Note: See also attached crash logs.