Gentoo's Bugzilla –
Attachment 366696 Details for
Bug 496682x11-drivers/xf86-video-intel-2.21.15 USE=sna with xorg-server-1.15.0 - .../work/xf86-video-intel-2.21.15/src/sna/sna_accel.c:15226:3: error: too many arguments to function 'DamageUnregister'