Hi, after getting ghc-ios working properly and a small ios app working, I was looking into what was missing from the ghc ios cross compiler [1]. One is TH for cross compilers, which lenses uses, if I'm not mistaken. The other directly ghc related one is dead code removal. I'm by no means an expert but why not take a stab, right? If someone could provide some initial leads where to look, what to read and failing tests, that would need to be fixed, that would be very awesome! Cheers, Moritz [1]: https://ghc.haskell.org/trac/ghc/wiki/Building/CrossCompiling/iOS