Instead of my old and semi-broken way of simply installing the Sensu gems globally, I’ve moved onto “porting” the official Omnibus package to a PKGBUILD.
This has been rather successful so far. The PKGBUILD is quite rudimentary at the moment, simply copying the files to /opt/sensu and leaving it at that, as I wasn’t too sure how to go about taking advantage of the “runsvdir” method that Sensu uses to manage the individual API, Server and Client services that power it.
But referring to /usr/share/sensu/systemd/README.md should get one clued into what needs to happen fairly easily once the package is built and installed. :)