Or perhaps you're testing with a local commit to Gaia? I see this when I try to `git submodule update`:

```
fatal: reference is not a tree: 598fcc7d1a94450b7f8d743204ddc37c7aea5467
Unable to checkout '598fcc7d1a94450b7f8d743204ddc37c7aea5467' in submodule path 'gaia'
```