This is a Unix agent
ERROR: Unexpected error in launching an agent. This is probably a bug in Jenkins
Also:   hudson.remoting.Channel$CallSiteStackTrace: Remote call to MacOS-Build-Server
        at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1784)
        at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:356)
        at hudson.remoting.Channel.call(Channel.java:1000)
        at hudson.FilePath.act(FilePath.java:1283)
        at org.jenkinsci.plugins.envinject.EnvInjectComputerListener.onOnline(EnvInjectComputerListener.java:144)
        at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:747)
        at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:437)
        at hudson.plugins.sshslaves.SSHLauncher.startAgent(SSHLauncher.java:641)
        at hudson.plugins.sshslaves.SSHLauncher.lambda$launch$0(SSHLauncher.java:458)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:829)
java.lang.reflect.InaccessibleObjectException: Unable to make private native java.lang.reflect.Field[] java.lang.Class.getDeclaredFields0(boolean) accessible: module java.base does not "opens java.lang" to unnamed module @5e1412be
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
    at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
    at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
    at org.jenkinsci.plugins.envinject.service.EnvInjectMasterEnvVarsSetter.getModifiers(EnvInjectMasterEnvVarsSetter.java:29)
    at org.jenkinsci.plugins.envinject.service.EnvInjectMasterEnvVarsSetter.call(EnvInjectMasterEnvVarsSetter.java:55)
    at org.jenkinsci.plugins.envinject.service.EnvInjectMasterEnvVarsSetter.call(EnvInjectMasterEnvVarsSetter.java:19)
    at hudson.remoting.UserRequest.perform(UserRequest.java:211)
    at hudson.remoting.UserRequest.perform(UserRequest.java:54)
    at hudson.remoting.Request$2.run(Request.java:377)
    at hudson.remoting.InterceptingExecutorService.lambda$wrap$0(InterceptingExecutorService.java:78)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
    at java.base/java.lang.Thread.run(Thread.java:833)