The necessary files to run eduke are the original DukeNukem3D data files. They are protected by copyright, and it is illegal to post them in this forum. For those reasons, they are not in the repository. However, you can find them googling on the internet, or in the original DukeNukem3D game CD, if you own one.
The eduke engine, on the other side, is opensource and free. Therefore, it can legally be in the repository.