walters, jlebon: Couple of questions: 
1. How does output of `rpm-ostree status --json` differ when a new deployment is staged?
2. In order to find the current deployment in the status json output, I want to iterate over all nodes in status[deployments] and find the one that has `"booted": true` and save <checksum>.<serial> of that deployment to a file for later comparison. I do this when rpm-ostree upgrade is run (right?)
3. Now, when ostree-finalize-staged is run, I want to get the <checksum>.<serial>  of the newly staged deployment from the status and compare that to the current one (hence question 1, or more specific, how is the staged deployment indicated in the status?). If it is not the same, the grub fallback countdown envs will be set to start.
4. does this approach even make sense? been struggling with this a bit :/