Hi,
I wanted to install libgpod via homebrew on the Mac. I created a formula for that.
https://github.com/stigi/homebrew/commit/26d5c6c023b76e88511b7ec7eda00c7bd4b704e8
When compiling it came up with two errors caused by incompatibility in sys/mount.h used in tools/generic-callout.c
Here's a patch describing my solution: https://gist.github.com/d030f697aaca3f917b4a