That version is our since June - should be at least as usntable in portgae tree. I shameless copied the ebuild from 1.8.6_p8 w/o any changes - works fine.
(and solves my issue here : http://forums.gentoo.org/viewtopic.php?p=7401072#7401072)
well, the test gives one failure : ./check_ttyname check_ttyname: FAIL /dev/pts/10 (sudo) vs. /dev/pts/9 (libc) make[1]: *** [check] Error 1 make[1]: Leaving directory `/var/tmp/portage/app-admin/sudo-1.8.7/work/sudo-1.8.7/src' make: *** [check] Error 2
*** This bug has been marked as a duplicate of bug 481392 ***
sudo-1.8.8 please: https://bugs.gentoo.org/show_bug.cgi?id=481392#c2