Re: ANNOUNCE: GHC 7.0.1 Release Candidate 1

I'm seeing errors like this in various places, which I guess are coming from the new type checker: Data/Array/Vector/Prim/BUArr.hs:663:3:     Couldn't match type `s' with `s3'       because this skolem type variable would escape: `s3'     This skolem is bound by the polymorphic type `forall s. ST s a'     The following variables have types that mention s       fill0 :: MBUArr s e -> ST s Int         (bound at Data/Array/Vector/Prim/BUArr.hs:669:5)     In the first argument of `runST', namely       `(do { marr <- newMBU n;              n' <- fill0 marr;              unsafeFreezeMBU marr n' })' I would love to hear an explanation about what they mean and what to do about them. (This one is from uvector.)