Error during creation

I get the following error during creation of a fresh dev container:

```
Running the postCreateCommand from Feature 'ghcr.io/julialang/devcontainer-features/julia:1'...

[11384 ms] Start: Run in container: /bin/sh -c /usr/local/julia-devcontainer-features/postcreate.jl
[20730 ms] postCreateCommand failed with exit code 1. Skipping any further user-provided commands.
```

I'm not able to see anything else.

My `devcontainer.json` file is just this:

```
{
"image": "mcr.microsoft.com/devcontainers/base:ubuntu",
"features": {
"ghcr.io/julialang/devcontainer-features/julia:1": {},
}
}
```