Reporting build failures on Leopard: Where?

Hello everyone, I may have a very stupid question: Where do I report build failures for packages on Leopard? I have trouble building quite a few ports on Mac OS 10.5, which build without failure on 10.4. Do I report directly to the package owner? Question then: How to get the package owner? Or this there a centralised "task force" for porting ports to 10.5, which I will report to? Sorry for that question. Best regards, Ralf Waldvogel