Yes an artifact is always a tarball, though I believe compression other than gzip is supported, including no compression.
It is mainly intended to be used to download tarballs that you produced specifically to be an artifact, as opposed to be for downloading random files from the internet.
And even it it worked now, your artifact would likely break in the future because the URL points at a git repo that is likely to change. Artifacts are static. If you need a new version of the data, you need a new artifact.
Some options:
- Base.download the data somewhere. The somewhere could be a scratch space as in Scratch.jl.
- DataDeps.jl (though I’ve never used it personally).
- Ask the repo owner nicely to make a GitHub release, which will automatically produce a .tar.gz of the whole repo, and use that as an artifact. But you’ll need to do this whenever you want to update the data.
- Copy the data into a .tar.gz yourself and put it somewhere static on the internet.