https://ci.wildfly.org/viewLog.html?buildId=277589&

======= Failed test run #1 ==========
java.lang.NoSuchFieldException: modifiers
	at java.base/java.lang.Class.getDeclaredField(Class.java:2610)
	at org.jboss.as.server.parsing.SystemPropertiesParsingTest.before(SystemPropertiesParsingTest.java:56)
...
======= Failed test run #2 ==========
java.lang.NoSuchFieldException: modifiers
	at java.base/java.lang.Class.getDeclaredField(Class.java:2610)
	at org.jboss.as.server.parsing.SystemPropertiesParsingTest.after(SystemPropertiesParsingTest.java:67)

Looks like this is specifically not meant to work:

https://stackoverflow.com/questions/56039341/get-declared-fields-of-java-lang-reflect-fields-in-jdk12

I'm going to just @Ignore this test. This is a test of WFCORE-4736 which amounts to a simple change to a log message to not log the system property value. Now the message clearly does not; one just needs to read it in the code to confirm that. The test is not actually checking for regressions to the fix; it's just checking the log message is invoked, which AFAICT was never in question. Reworking this text to deal with the above problem is not worth further effort.