fstat() broken in iOS 4

When rebuilding a perfectly working iPhone project on iOS 4 SDK, I found out that fstat() returns a bogus value in the stat.st_size field. Observed on iPhone 3 si开发者_高级运维mulator with iOS 4. Looks like there's a discrepancy between the binary layout of the stat structure in the program and in the API. I've found a workaround (lseek() to the end), but this looks like a bug to me. How do I submit a bug report to Apple, please?

https://bugreport.apple.com/