the root of the problem here is that ant was removed from the android build tools after KitKat I believe? In any case, it's necessary for lime to download the android sdk it needs in order for ant to be there.
Using an up to date android sdk elsewhere on the system may cause some problems for you since build.xml will continue to not be found unless the sdk is downgraded. My solution was to have a completely different android sdk just for lime, seems to work ok compiling with Android sdk 19.