In order to prevent this PR from becoming too large to review, I left the spread test, the part of this feature which makes it work with user daemons (left a TODO) and the addition of ~/Snap, for follow-up PRs.

I tried implement the retries with as little as possible change, but it's quite hard to do that and keep the code clean with the current system. If you prefer less changes, I'm happy to go back to just the first two commits:

This PR contains some minor changes, each in a separate commit so I can easily remove them if they are not wanted.

We've stated what's required multiple times now: #14540 (comment) #14540 (comment), and the follow up arguments weren't convincing. Follow Rafael's advice in new smaller PRs to advance this or it'll simply stay closed

When submitting new methods for consideration, it is best if each method (or tightly related set of methods) is in it's own pull request. If you have only one method to submit then a simple commit will do the trick. If you have more than one it best to use separate branches. Let me emphasizes this point because it makes it much more likely that your pull request will be merged. If you submit a bunch of methods in a single pull request, it is very likely that it will not be merged even if methods you submitted are accepted!