libsigsegv 2.5 is out. Contrary to 2.4 it compiles on x86-macos (portage prefix), which is why having it would be nice.
dev-libs/libsigsegv-2.6 is in portage. FYI, it emerges correctly and passes 5 tests out of 5 on HPPA with gcc-4.3.2, CFLAGS=CXXFLAGS="-O2 -pipe -march=2.0", FEATURES="test userpriv -usersandbox", MAKEOPTS="-j3"