According to `helix/rev2/keymaps/fraanrosi/readme.md`, this keymap should be compiled with the following command:
```
make helix/rev2/under:fraanrosi
```
Therefore, when compiling all helix keymaps with the following command, an error occurs when compiling `fraanrosi`.
```
make helix:all
```
Therefore, add `LED_UNDERGLOW_ENABLE = yes` to `keymaps/fraanrosi/rules.mk` to suppress the error.