The objective of this task is to create a loader for Nix/Guix distributions. These distributions expose a `sources.json` containing all sources used at a specific moment.
This work could be split into the following diffs:
- [x] D2792: Create a loader able to load archives
- [x] D2807: Add a pointer in the snapshot to the commit used to generate the sources.json file
- [x] T2411: Deploy current nixguix loader version (fix issues along the way)
- [ ] D2854: Support files that are not archive but plain text (stand-by)
- [ ] Use all mirrors instead of just the first one.
- [ ] Implement a mechanism to subscribe to a list of `sources.json`.
- [ ] Support others types of source (git for instance)...