DragonFly’s size_t and ssize_t have been modified. This creates more exact warnings of 64-bit problems when building on 32-bit systems. It may cause trouble with pkgsrc, though, so it will be reverted before the release (on 32-bit) if needed.
Be careful if you’re running bleeding-edge DragonFly. A full buildworld is needed because of this.
Relevant articles:
20 issues of porting C++ code on the 64-bit platform
http://www.viva64.com/art-1-2-599168895.html
A 64-bit horse that can count
http://www.viva64.com/art-1-2-377673569.html
Safety of 64-bit code
http://www.viva64.com/art-1-2-416605136.html
It’s already reverted on 32-bit.