A DESCRIPTION OF THE PROBLEM :
https://bugs.openjdk.org/browse/JDK-8343757 shows release notes containing this:

log_info(gc)("A\n[gc] B");

However, in the final release notes at https://jdk.java.net/24/release-notes#JDK-8288298 this has been changed to:

log_info(gc)("An[gc] B");

And then the example no longer makes sense.