Cowsay does not emerge correctly under OSX. It has two issues:
1. Dependance on GNU sed (Depends on bug 58087)
2. dobin bug (57878) fixed in cvs.
I've included a patch for the sed issues in the ebuild.
Created attachment 36121 [details, diff]
Fixes sed issues with cowsay
With the dobin fix and the gsed aliases, the cowsay ebuild no longer needs these changes.
Closing out bugs that've been resolved for a while now...