Don't unwrap in Listener::dialer

tarpc/src/transport/unix.rs

@@ -34,7 +34,11 @@ impl super::Listener for UnixListener {
         self.accept().map(|(stream, _)| stream)
     }
     fn dialer(&self) -> io::Result<UnixDialer<PathBuf>> {
-        self.local_addr().map(|addr| UnixDialer(addr.as_pathname().unwrap().to_owned()))
+        self.local_addr().and_then(|addr| match addr.as_pathname() {
+            Some(path) => Ok(UnixDialer(path.to_owned())),
+            None => Err(io::Error::new(io::ErrorKind::AddrNotAvailable,
+                                       "Couldn't get a path to bound unix socket")),
+        })
     }
 }