Works nicely with net-libs/libnet-1.1.2, though.
Created attachment 212629 [details] gdb backtrace [hppa]
Debian had a nice patch that fixes the issue. Leaving this open a while so people can find the fix: re-emerge =net-libs/libnet-1.1.4. (I didn't bump the revision because stabilisation is in progress (bug #289857).
Jeroen, thank you very much for the fix. Next time, please, always bump revision in other case we'll get new bug reports on the same issue and tracking things became practically impossible. Revision bumped archs bug will be readded.