Add link to scripted function definition.

src/module/mod.rs

@@ -2140,7 +2140,11 @@ impl Module {
 
         // Variables with an alias left in the scope become module variables
         for (_name, value, mut aliases) in scope {
-            // It is an error to export function pointers that refer to encapsulated local functions
+            // It is an error to export function pointers that refer to encapsulated local functions.
+            //
+            // Even if the function pointer already links to a scripted function definition, it may
+            // cross-call other functions inside the module and won't have the full encapsulated
+            // environment available.
             #[cfg(not(feature = "no_function"))]
             if let Some(fn_ptr) = value.downcast_ref::<crate::FnPtr>() {
                 if ast.iter_fn_def().any(|f| f.name == fn_ptr.fn_name()) {