/usr/lib/GNUstep/Frameworks/netclasses.framework/libnetclasses.so is in libnetclasses-dev 1.06.dfsg-7build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/GNUstep/Frameworks/netclasses.framework/Versions/Current/libnetclasses.so