Project is not for IOS
This will not run on iOS contrary to articles that link here
The project as currently set up is a macOS project, but the source files should work when transplanted into an iOS project. Admittedly I haven't tested in a number of years, but it worked when I first wrote it.
This is a super old project and I didn't think anyone besides @mattneub cared about it, so I've never done any work to try and make the project file work for multiple platforms.
Was this issue filed because the project file only targets macOS, or did you actually try adding the source files to an iOS project and ran into problems?
All I can tell you is that FeedParser is the basis for TidBITS News, which is most certainly an iOS app. I'm not aware of any sense in which it "will not run on iOS"!