Comment # 2 on bug 98993 from smoki

 BTW i tried not with dosbox git and not just git mesa, dosbox package from
Debian Sid, mesa currently there is 13.0.2, etc...

 I also have DRI3 flashing with rtcw game, this looks like same issue to me :)

 https://packages.debian.org/sid/dosbox
 https://packages.debian.org/sid/rtcw