[exim] Can't build 4.63 on solaris 8

Compiling Exim 4.63 on Solaris 8,

I got this error:
make: Fatal error: Don't know how to make target `dk.h'

I've not chosen to use any of the experimental modules, and don't seem to
be able to persuade the build process to work. Is there a known workaround?

--
Ian Eiloart
IT Services, University of Sussex