$ sudo apt install systemd-sysv
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
libseccomp2 libsystemd0 systemd
Suggested packages:
systemd-ui systemd-container
Recommended packages:
libpam-systemd dbus
The following packages will be REMOVED:
init sysvinit-core
The following NEW packages will be installed:
libseccomp2 libsystemd0 systemd systemd-sysv
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
init sysvinit-core (due to init)
0 upgraded, 4 newly installed, 2 to remove and 26 not upgraded.
Need to get 3,849 kB/3,883 kB of archives.
After this operation, 18.7 MB of additional disk space will be used.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
?]
But, both the methods that you have provided [1] work.
Thus it becomes
-----------------------
apt search can't find the package. I couldn't check this
out using Devuan repos (see my thread about apt update error),
but using Debian repositories apt didn't see the presence of
the package.