Extra SLF4J noise in console?

I'm seeing these kinds of messages when building the play-2.6 sample:

> SLF4J: Class path contains multiple SLF4J bindings.
> SLF4J: Found binding in [jar:file:/Users/sterling/.gradle/caches/5.1-20181207050309+0000/generated-gradle-jars/gradle-api-5.1-20181207050309+0000.jar!/org/slf4j/impl/StaticLoggerBinder.class]
> SLF4J: Found binding in [jar:file:/Users/sterling/tmp/gradletest/lib/gradle-logging-5.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
> SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
> SLF4J: Actual binding is of type [org.gradle.internal.logging.slf4j.OutputEventListenerBackedLoggerContext]

This might be a gradle/gradle bug.