TypeError: Cannot read properties of undefined (reading '0') in devContainersSpecCLI.js for some features

For some reasons, this feature causes devcontainers to choke:
```
"features": {
"ghcr.io/devcontainers-community/features/llvm:3.0.0": {},
// "./features-llvm": {},
```
[build.log](https://github.com/devcontainers/cli/files/13575679/build.log)

3.0, 3, and latest gives same problem. But cloning the repo and refer to it locally works.

It's not clear what the problem is or how to even begin to debug this problem with the minified script. Do you guys offer a debug build somewhere?