= note: expected type `std::boxed::Box<futures::FutureResult<(fs::hash::Fingerprint, usize), std::string::String>>`
               found type `std::boxed::Box<futures::Join<futures::JoinAll<std::iter::Map<std::vec::IntoIter<std::path::PathBuf>, [closure@src/main.rs:149:54: 159:8 root_for_dirs:_, store1:_, posix_fs1:_]>>, futures::JoinAll<std::iter::Map<std::vec::IntoIter<std::path::PathBuf>, [closure@src/main.rs:161:56: 184:8 root_relative_to_posixfs:_, store:_, posix_fs:_]>>>>`