home-syncthing-service-type wants /root paths, yet syncthing can work

[Sébastien Lerique]

Hi Guix! And dear helpers and devs,

I'm running into a weird failure of home-syncthing-service-type.

Running syncthing manually from the terminal works fine (here's an 
example log: <https://pastebin.com/1dLMKkyK>).

So I Ctrl-C syncthing, then add home-syncthing-service-type to my 
home-configuration 
<https://gitlab.com/wehlutyk/guix-config/-/blob/master/home-configuration.scm> 
(bottom lines).

After restarting, home-syncthing-service-type fails synchronizing 
because it bases all user folders inside /root, to which it doesn't have 
writing rights. This happens whether all syncthing configurations in 
`.local/state/syncthing` had been removed in the meantime or not. Here's 
a log: <https://pastebin.com/14LwbvRn>

Could this be a bug? A mistake in the configuration files? In case it's 
useful, the system config is 
<https://gitlab.com/wehlutyk/guix-config/-/blob/master/config.scm>, and 
the versions:

sl@beoga ~> guix describe
Generation 3    Jan 03 2024 23:08:17    (current)
  guix 7b0863f
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 7b0863f07a113caef26fea13909bd97d250b629e
  guix-science 4e7057c
    repository URL: https://github.com/guix-science/guix-science.git
    branch: master
    commit: 4e7057ceafba901f619bac068c74c6df158fd4ec
  nonguix 8956906
    repository URL: https://gitlab.com/nonguix/nonguix
    branch: master
    commit: 8956906f6bed6709e71f0c26ed6a3620f40dc487

Best to all, and thanks for any answer!
Sébastien