Running a Spring-Boot 1.4 app unit test with JUnit 4, (logging via SLF4J and Log4j 2.x), my output window begins:
SYSTEM_OUTPUT/Library/Java/JavaVirtualMachines/jdk1.8/Contents/Home/bin/java -ea -Didea.launcher.port=7534
and then every line after that ends with "NORMAL_OUTPUT", à la:
14:48:36.135 DEBUG [main] org.springframework.test.context.BootstrapUtils - Instantiating CacheAwareContextLoaderDelegate from class [org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate]NORMAL_OUTPUT
It's just an irritation, but it would be nice to be rid of it.
I'm 98% sure this wasn't happening prior to 2016.3 (I'm using the "Ultimate" edition).
(BTW: the "NORMAL_OUTPUT" and "SYSTEM_OUTPUT" tokens do not appear in the on-disk log file, which tells me it's not due to log4j 2.x. SLF4J's jcl-over-slf4j jar is in the path, to capture Spring's logging. No change in version for any of those.)