I'm the upstream maintainer for Sopwith. I'd like to point out that
while Sopwith _can_ use GTK2 for its graphical interface, the preferred
method as been SDL for several years. We had too many problems with GTK2
and deprecated it as a front-end. Sopwith does not have a hard
dependency on GTK and so this recommended dependency can simply be
removed from the Debian package.
There isn't any need for us to port to GTK3 because we haven't been
maintaining the GTK2 port up to this point. The GTK build option can
just be disabled downstream.
Jesse
