The darcs port on FreeBSD has been marked as BROKEN for a few a while; here’s the explanation. Basically, darcs 1.0.2 used some ghc internal APIs that changed with ghc 6.4. I was able to compile darcs 1.0.2 ok though, since my machine still has 6.2.2 installed because the ghc 6.4_1 port wouldn’t compile.