message: build fix
  build fix
diff: @@ -16,6 +16,8 @@ extern crate log;
  use std::any::Any;
  use std::collections::{btree_map, BTreeMap};
  +#[cfg(feature = "virtiofs")]
  +use std::ffi::OsString;
  use std::ffi::{CStr, CString};
  use std::fs::File;
  use std::io;
  