I'm getting this error with 5.0.8.Final:
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
When debugging, I found that StaticLoggerBinder got shaded:
java.lang.NoClassDefFoundError: org/ocpsoft/prettytime/shade/org/slf4j/impl/StaticLoggerBinder
I suspect it is related to the shading of slf4j-api from fc37c10, SLF4J needs to be able to pick up its implementation at the expected location since it's provided (in our case) by Log4j 2.