[fine] Automatic rebase support for CST

fine/build.rs

@@ -33,8 +33,9 @@ fn generate_test_for_file(path: PathBuf) -> String {
     }
 
     let concrete_comparison = if let Some(concrete) = concrete_stuff {
+        let display_path = path.display().to_string();
         quote! {
-            crate::assert_concrete(&_tree, #concrete)
+            crate::assert_concrete(&_tree, #concrete, #display_path)
         }
     } else {
         quote! {}