Using a mutable reference breaks clone.

src/parser/text.rs

@@ -133,7 +133,7 @@ pub fn paragraph_end(input: &str) -> Res<&str, &str> {
 }
 
 pub fn document(input: &str) -> Res<&str, Vec<(Vec<TextElement>, &str)>> {
-    let initial_context = NomContext::new(&paragraph_end);
+    let initial_context = NomContext::new(&mut paragraph_end);
     todo!()
     // many1(parser_with_context!(paragraph)(initial_context))(input)
 }