Are There Problem Reporting Systems for Linux

Lazy Bones asks "Can anyone recommend a good 'off the shelf' Problem reporting for Linux. I am working in a multiply supplier development environment and we already use Linux/appache for interproject information. It would be nice to have a web based tool to document problems between Stakeholders. The current system is based on Access and is unusable. Does anyone have experience of using the PHP based tools such as 'Keystones'?"