Found a bug today that made me groan in frustration.

It appears that the official elasticsearch debian package checks if the system's init daemon is systemd by... Checking if systemctl binary is available.

Issue is... Systems might contain that binary while using a different init, as the binary is part of the "systemd" package.

To actually switch to systemd however, the package systemd-sysv has to be installed, which creates a link from /bin/init to systemd's main executable.

What happens when your system doesnt use systemd then? The postinstall/preremove scripts fail as systemctl fails to talk to the system bus, and thus, the installation is marked as failed!

Oversights like this are exactly the reason behind my systemd dislike. We never wanted the systemd package, but another key package suddenly added it as a dependency one day...

Now to see if this is reported as a bug already, and if not, to report it myself...

(also, who checks for init by looking for the init's management utility?! Its like I checked if sysvinit is installed by checking if update-rc.d is installed!
And not like figuring out the system's init daemon is hard anyway! Just check /bin/init, or, better yet, check for process with pid 0!)