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...