Finished a package for NetBSD a while ago, as a "Work In Progress" (community-driven) pkgsrc package.
Pkgsrc ("package source") is a cross-platform framework for building packages, originating in the NetBSD project, but it can be (and has been) used on many platforms like OS X, Linux, Solaris, AIX and the other BSDs.
There were no issues at all in packaging this software. Kudos to the developers for producing such a high-quality codebase (and a fantastic job in general in faithfully reproducing this great game!)
See
https://pkgsrc.se/wip/openxcom for more info on the package.
