The installation program of tracball try to create this file: /usr/share/applnk/Games/Arcade/trackballs.desktop wich 1) is bad (tm) 2) make the ebuild fails with sandbox and/or userpriv
not related to usersandbox ... i just made it happen over here w/out it it didnt come up while testing because i didnt have a /usr/share/applnk/Games/ ;) it'll be fixed later today
ok updated the ebuild and patched the install http://cvs.gentoo.org/cgi-bin/viewcvs.cgi/gentoo-x86/app-games/trackballs/trackballs-0.9.0.ebuild.diff?r1=1.1&r2=1.2