The section of the ELOG Administrator's Guide https://elog.psi.ch/elog/adminguide.html describing how to build and install ELOG on a Mac OS X system has worked well for me for several years, even though there have been warnings that the "load" and "unload" subcommands of the "launchctl" command have been deprecated for some time.  After trying my luck again on a new Mac with the latest operating system, I encountered errors of the type "Load failed: 5: Input/output error" when attempting to follow these instructions.

After a bit of searching around, I used information at the page https://www.alansiu.net/2023/11/15/launchctl-new-subcommand-basics-for-macos/ to deploy the more current subcommands as follows:

sudo launchctl enable system/ch.psi.elogd
sudo launchctl bootstrap system /Library/LaunchDaemons/ch.psi.elogd.plist 

sudo launchctl disable system/ch.psi.elogd

Once the above can be verified, perhaps the instructions in the Administrator's Guide can be updated accordingly.