fix copy

src/copy.rs

@@ -143,7 +143,7 @@ async fn check_path_validity(store_path: &str) -> anyhow::Result<bool> {
 
 async fn copy_path(store_path: &str, copy_to: &str) -> anyhow::Result<()> {
     let mut cmd = WrappedChild::new(
-        Command::new("nix").args(&["copy", "--to", copy_to]),
+        Command::new("nix").args(&["copy", "--to", copy_to, store_path]),
         Some(format!("nix copy {}", store_path)),
     )?;
     loop {