I would be thrilled to see this ported to GitLab CI. This is an incredibly (for lack of a better word) sexy tool on top of Nix, and would perfectly fit a use case we have for using Nix for caching build artifacts.

Nice. The GitLab caching API is basically saving and restoring a folder, so if you allow pointing to a local folder instead of the GitHub API you should be good!

Is the same true for Azure Pipelines? Given Actions forked from Pipelines I'd imagine it would be straightforward.

I would love to use this kind of thing with GitLab CI (and AzDO) at work!