Hello, in-tree version 2.0.10 is very old and doesn't compile recent tcl (see bug 482318). New version is available: http://www.csse.uwa.edu.au/cnet/ Looks like it should be fetch-restricted: author requires to fill a form before downloading and I can't find a way for a direct download. This seems to be compatible with GPL since source code is still freely available for everyone, but this approach is a maintenance menace of course.
Created attachment 356864 [details] cnet-3.2.4.ebuild Good news: I updated ebuild and Gentoo patch for cnet-3.2.4. Bad news: it still fails to build with tcl-8.6 with the same error as in-tree version. API changes are not trivial here. I'm uploading ebuild and patch so it may help you in further work.
Created attachment 356866 [details, diff] cnet-3.2.4-gentoo.patch
+ 16 Jan 2014; Sergey Popov <pinkbyte@gentoo.org> +cnet-3.2.4.ebuild, + +files/cnet-3.2.4-gentoo.patch: + Version bump, wrt bug #482320. Thanks to Andrew Savchenko <bircoph AT + gmail.com> for initial ebuild and patch