workaround

modules/neovim/_editing.nix

@@ -9,6 +9,22 @@
         enable = true;
       };
 
+      # Workaround: Neovim 0.11.x does not implement the is? / is-not? treesitter
+      # predicates, but newer grammar query files (tree-sitter-nix, tree-sitter-javascript)
+      # use (#is-not? local) to scope highlights to non-local identifiers.
+      # Register no-op handlers to suppress the error; remove once Neovim
+      # ships with built-in support for these predicates.
+      extraConfigLua = /* lua */ ''
+        -- (#is?) always returns false (node never "is" something)
+        vim.treesitter.query.add_predicate("is?", function()
+          return false
+        end, { force = true })
+        -- (#is-not?) always returns true (node is always "not" something)
+        vim.treesitter.query.add_predicate("is-not?", function()
+          return true
+        end, { force = true })
+      '';
+
       plugins.treesitter = {
         enable = true;
         highlight.enable = true;