Rust borrowing with loop and Vec

I simply try to build a kind of tree: having one root node and then want to add nodes as subnodes to the root node. It runs into this error and I cannot get my head around what is going wrong.

#[derive(Clone)]pub struct Node {    id: String,    file: FileContent,     nodes: Vec<Node>,}impl Node {    pub fn new(file:FileContent) -> Self {        Self {            id: file.path.clone(),            file: file.clone(),            nodes:Vec::<Node>::new(),        }    }    pub fn add(mut self, node: Node) -> Self{        self.nodes.push(node.clone());        self    }}#[derive(Clone)]pub struct FileContent {    path: String,    length: usize,    content_type: String,}pub fn create_test_file_content() -> Vec<FileContent> {    let mut file_content = Vec::<FileContent>::new();    file_content.push(FileContent {path:String::from("r/a1/a2"),length: 1,content_type: String::from("DIRECTORY"),});    file_content.push(FileContent {path:String::from("r/b1/ba2"),length: 1,content_type: String::from("DIRECTORY"),});    file_content.push(FileContent {path:String::from("r/b1/bb2"),length: 1,content_type: String::from("DIRECTORY"),});    file_content}fn main() {    let filecontent = create_test_file_content();    let root = Node::new(FileContent {path:String::from("root"),length: 1,content_type: String::from("DIRECTORY")});    for fc in filecontent {        let node = Node::new(fc);        root.add(node);    }}

When I follow the suggestion of cloning the root node, then it works but why should I do this? 'root' is still in the same scope and only struct member 'nodes'-changes.

Many thanks