| Also, is there a better list for this question? I half-heartedly tried | haskell.org's list of mailing lists for an appropriate place for GHC | bugs but didn't find one. Yes, there is a mailing list specifically for ghc bugs http://www.haskell.org/ghc/docs/latest/html/users_guide/introduction-GHC.htm... | When I load my program, GHC spits these messages at me, but doesn't | fail Any idea what might be causing this or how to figure that out? | | Var/Type length mismatch: | [] | [a{tv aGIf} [tau]] This is definitely a bug. The first thing is to compile (all your modules) with -dcore-lint. That often localises the problem dramatically. Even if that localises it, I may well need to be able to reproduce it myself, so if you felt able to shrink your program by deleting stuff, or (next best) tar up the entire thing so we can build it, that would be great. thx Simon