For non LocationAwareLoggers, Throwables are silently ignored. See:

https://github.com/qos-ch/slf4j/blob/v_1.6.2/log4j-over-slf4j/src/main/java/org/apache/log4j/Category.java#L181

For trace(Object message, Throwable t), the Throwable is silently ignored. See:

https://github.com/qos-ch/slf4j/blob/v_1.6.2/log4j-over-slf4j/src/main/java/org/apache/log4j/Logger.java#L75