Note from the developer
I am no longer working on apt-cyg. As far as I know, it works.
However it was written quite a while ago by reverse engineering the files used by Cygwin's setup.exe program. It doesn't share any code with setup.exe, and if setup.exe is modified in such a way that assumptions made by apt-cyg no longer apply, apt-cyg will break.
apt-cyg is an infrastructure program and probably belongs in Cygwin rather than here, but as far as I know, RedHat is no longer paying more than one or two engineers to work on Cygwin and they are unlikely to do anything with apt-cyg or other, similar programs that are out there.
Because I got dragged into a time-consuming and unpleasant law suit involving apt-cyg, I am very unlikely to put more time and effort into it anytime soon, even though I won. I write open source software because I enjoy it, not so I can get involved in meaningless conflicts.
If you would like to contribute to apt-cyg, the best way to do that is to fork it. You don't need my permission to do that, just follow the license.