All,

--8<---------------cut here---------------start------------->8---
~ λ while :; do sudo herd restart tor; done
Service tor is not running.
Service tor has been started.
Service tor has been stopped.
Service tor could not be started.
Service tor is not running.
Service tor could not be started.
^C
~ λ pgrep tor
22926
23004
--8<---------------cut here---------------end--------------->8---

This has (this year) happened to nginx in tight edit.conf/restart 
loops too, but I can't say if the two are at all related.

Here's the output of ‘herd status’ but it's not very useful to me:

--8<---------------cut here---------------start------------->8---
λ sudo herd status
Started:
 + dovecot
 + file-system-/dev/pts
 + file-system-/dev/shm
 + file-system-/gnu/store
 + file-systems
 + guix-daemon
 + loopback
 + mcron
 + networking
 + nginx
 + root
 + root-file-system
 + smtpd
 + ssh-daemon
 + syslogd
 + term-tty1
 + udev
 + urandom-seed
 + user-file-systems
 + user-processes
 + virtual-terminal
Stopped:
 - tor
One-shot:
 * host-name
 * user-homes
--8<---------------cut here---------------end--------------->8---

He looks guilty:

--8<---------------cut here---------------start------------->8---
λ sudo cat /var/run/tor/tor.pid
cat: /var/run/tor/tor.pid: No such file or directory
--8<---------------cut here---------------end--------------->8---

From ps auxwww:

--8<---------------cut here---------------start------------->8---
~ λ head -n6 /gnu/store/5ivhkbd0pzhnnmk38yn7cygcyd02kkk5-torrc
### These lines were generated from your system configuration:
User tor
DataDirectory /var/lib/tor
PidFile /var/run/tor/tor.pid
Log notice syslog
### End of automatically generated lines.
--8<---------------cut here---------------end--------------->8---

No contradictory lines added.

Kind regards,

T G-R