NPE in log4j2 in unit test MainDeployTest

mvn -B -Dtest=MainDeployTest#testClusterModeFail1 test

1:42:10 WARN bstractEventExecutor A task raised an exception. Task: io.vertx.core.impl.EventLoopContext$$Lambda$182/0x0000000800ecbc40@d9cd2d8
java.lang.NullPointerException: null
at org.apache.logging.log4j.util.StackLocator.calcLocation(StackLocator.java:79) ~[log4j-api-2.13.1.jar:2.13.1]
at org.apache.logging.log4j.util.StackLocatorUtil.calcLocation(StackLocatorUtil.java:78) ~[log4j-api-2.13.1.jar:2.13.1]
at org.apache.logging.log4j.core.config.LoggerConfig.log(LoggerConfig.java:409) ~[log4j-core-2.13.1.jar:2.13.1]
at org.apache.logging.log4j.core.config.AwaitCompletionReliabilityStrategy.log(AwaitCompletionReliabilityStrategy.java:63) ~[log4j-core-2.13.1.jar:2.13.1]
at org.apache.logging.log4j.core.Logger.logMessage(Logger.java:153) ~[log4j-core-2.13.1.jar:2.13.1]
at org.apache.log4j.Category.forcedLog(Category.java:388) ~[log4j-1.2-api-2.13.1.jar:2.13.1]
at org.apache.log4j.Category.log(Category.java:499) ~[log4j-1.2-api-2.13.1.jar:2.13.1]
at io.vertx.core.logging.Log4jLogDelegate.log(Log4jLogDelegate.java:151) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.logging.Log4jLogDelegate.error(Log4jLogDelegate.java:66) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.impl.logging.LoggerAdapter.error(LoggerAdapter.java:94) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.impl.ContextImpl.reportException(ContextImpl.java:229) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.impl.EventLoopContext.reportException(EventLoopContext.java:26) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.impl.AbstractContext.emit(AbstractContext.java:185) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.vertx.core.impl.EventLoopContext.lambda$execute$0(EventLoopContext.java:42) ~[vertx-core-4.0.0-milestone4.jar:4.0.0-milestone4]
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) [netty-common-4.1.42.Final.jar:4.1.42.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:510) [netty-common-4.1.42.Final.jar:4.1.42.Final]
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:309) [netty-transport-native-epoll-4.1.15.Final-linux-x86_64.jar:4.1.15.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1044) [netty-common-4.1.42.Final.jar:4.1.42.Final]
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) [netty-common-4.1.42.Final.jar:4.1.42.Final]
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [netty-common-4.1.42.Final.jar:4.1.42.Final]
at java.lang.Thread.run(Thread.java:830) [?:?]

Problem is with Java 14.. Not with Java 8 (other versions not tested).