error[E0277]: the trait bound `std::vec::Vec<std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String>>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, _>>>: std::iter::FromIterator<std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String> + std::marker::Send>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, [closure@src/main.rs:153:21: 158:12 dir:_]>>>` is not satisfied
   --> src/main.rs:160:12
    |
160 |           .collect::<Vec<Box<futures::AndThen<Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String>>, Result<bazel_protos::remote_execution::DirectoryNode, String>, _>>>>());
    |            ^^^^^^^ a collection of type `std::vec::Vec<std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String>>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, _>>>` cannot be built from an iterator over elements of type `std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String> + std::marker::Send>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, [closure@src/main.rs:153:21: 158:12 dir:_]>>`
    |
    = help: the trait `std::iter::FromIterator<std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String> + std::marker::Send>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, [closure@src/main.rs:153:21: 158:12 dir:_]>>>` is not implemented for `std::vec::Vec<std::boxed::Box<futures::AndThen<std::boxed::Box<futures::Future<Item=(fs::hash::Fingerprint, usize), Error=std::string::String>>, std::result::Result<bazel_protos::remote_execution::DirectoryNode, std::string::String>, _>>>`