/usr/include/GNUstep/Frameworks/RSSKit.framework/ is in librsskit-dev 0.4-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/GNUstep/Frameworks/RSSKit.framework/Headers
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/Atom03Parser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/Atom10Parser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/AtomParser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/DOMParser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/DublinCore.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/FeedParser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/NewRSSArticleListener.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSS10Parser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSS20Parser.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSArticle+Storage.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSArticle.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSArticleCreationListener.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSArticleProtocol.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSFactory.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSFeed+Fetching.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSFeed+Storage.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSFeed.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSFeedProtocol.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSKit.h
/usr/include/GNUstep/Frameworks/RSSKit.framework/Versions/0d/RSSLinks.h