seavan is a crate which wraps files in a container layer for later composition.
At time of writing you can't mount an OCI artifact while building a Docker image, whereas you can do:
```Dockerfile
FROM someimage
RUN --mount=type=bind target=/mnt/imagemount,from=seavanpkg/myrandomfile:1.2.3 rpm -ivh /mnt/imagemount
```
using Docker Buildkit to mount image layers at a specific directory, without having to copy those files into the image itself.
"seavan" is apparently another name for a shipping container - seemed like an apt choice!