The following tests failed in the JDK18 CI:

tools/jar/multiRelease/Basic1.java
tools/jar/multiRelease/Basic.java
tools/jar/multiRelease/ApiValidatorTest.java
tools/jar/modularJar/Basic.java

Here's a snippet from the tools/jar/multiRelease/Basic1.java log file:

----------System.out:(100/6052)----------
config Basic1.setup(): failure
java.lang.RuntimeException: error: invalid flag: -J-Xmx768m
Usage: javac <options> <source files>
use --help for a list of possible options

at MRTestBase.javac(MRTestBase.java:122)
at Basic1.setup(Basic1.java:55)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:577)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
at org.testng.internal.MethodInvocationHelper.invokeMethodConsideringTimeout(MethodInvocationHelper.java:61)
at org.testng.internal.ConfigInvoker.invokeConfigurationMethod(ConfigInvoker.java:366)
at org.testng.internal.ConfigInvoker.invokeConfigurations(ConfigInvoker.java:320)
at org.testng.TestRunner.invokeTestConfigurations(TestRunner.java:617)
at org.testng.TestRunner.beforeRun(TestRunner.java:607)
at org.testng.TestRunner.run(TestRunner.java:578)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
at org.testng.TestNG.runSuites(TestNG.java:1069)
at org.testng.TestNG.run(TestNG.java:1037)
at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:94)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:577)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:312)
at java.base/java.lang.Thread.run(Thread.java:833)