So I looked a bit deeper and found out that the chapter was about the creation of statically typed loggers and dictionaries, either at runtime or through annotation processing. And while I fail to see the point of typed loggers (Why would I reuse log statements? Sounds like duplicated code), I like the solution to typed dictionaries.
But Solder's logging tooling is not based on SLF4J as I would have expected, but on JBoss Logging, a library that I cannot find a proper link to as there is only outdated information. So, why another logging library? JBoss Logging aims to abstract away other logging frameworks. Well, that's exactly what SLF4J is there for! SLF4J's API has been stable from the beginning and the typed loggers could have easily been built on top of it.
Now users will get even more headaches trying to get something as simple as logging to run.