or you could, I think, say

| foo :: Q Dec -> Q () | foo qd = do d<-qd | return (out' d) | | outGen :: Q [Dec] | outGen = do let d = reifyDecl Tree | dec1<-clause [pvar "x"] (normal [|foo d|]) [] | return [Fun "out" [dec1]]

For info, this does not work either: ghc gives a "No instance for (Lift Decl)" (instead of a "No instance for (Lift Dec)"), which doesn't surprise me. However, I've got a working solution, and I'm fine with that. Best wishes, fr.