ConnectorServerTest fails on macOS, because InetAddress.getLocalHost().isLoopbackAddress() is true

[afarber]

Jetty version(s)
Jetty 12.0.x

Jetty Environment
core

Java version/vendor (use: java -version)
openjdk version "21.0.8" 2025-07-15
OpenJDK Runtime Environment Homebrew (build 21.0.8)
OpenJDK 64-Bit Server VM Homebrew (build 21.0.8, mixed mode, sharing)

OS type/version
macOS 15.5 (24F74)

Description
Good evening, the following 3 tests fail, when I run "mvn install" on my Macbook Air M1 with Homebrew OpenJDK 21, because (differently from Linux) InetAddress.getLocalHost() is same as InetAddress.getLoopbackAddress():

[ERROR] Tests run: 11, Failures: 3, Errors: 1, Skipped: 0, Time elapsed: 0.594 s <<< FAILURE! -- in org.eclipse.jetty.jmx.ConnectorServerTest
[ERROR] org.eclipse.jetty.jmx.ConnectorServerTest.testNoRegistryHostBindsToHost -- Time elapsed: 0.015 s <<< FAILURE!
org.opentest4j.AssertionFailedError: Expected java.net.ConnectException to be thrown, but nothing was thrown.
	at org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:152)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:73)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:35)
	at org.junit.jupiter.api.Assertions.assertThrows(Assertions.java:3128)
	at org.eclipse.jetty.jmx@12.0.24-SNAPSHOT/org.eclipse.jetty.jmx.ConnectorServerTest.testNoRegistryHostBindsToHost(ConnectorServerTest.java:79)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

[ERROR] org.eclipse.jetty.jmx.ConnectorServerTest.testNoRMIHostBindsToHost -- Time elapsed: 0.010 s <<< FAILURE!
org.opentest4j.AssertionFailedError: Expected java.net.ConnectException to be thrown, but nothing was thrown.
	at org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:152)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:73)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:35)
	at org.junit.jupiter.api.Assertions.assertThrows(Assertions.java:3128)
	at org.eclipse.jetty.jmx@12.0.24-SNAPSHOT/org.eclipse.jetty.jmx.ConnectorServerTest.testNoRMIHostBindsToHost(ConnectorServerTest.java:147)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

[ERROR] org.eclipse.jetty.jmx.ConnectorServerTest.testNoRegistryHostNonDefaultRegistryPort -- Time elapsed: 0.014 s <<< FAILURE!
org.opentest4j.AssertionFailedError: Expected java.net.ConnectException to be thrown, but nothing was thrown.
	at org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:152)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:73)
	at org.junit.jupiter.api.AssertThrows.assertThrows(AssertThrows.java:35)
	at org.junit.jupiter.api.Assertions.assertThrows(Assertions.java:3128)
	at org.eclipse.jetty.jmx@12.0.24-SNAPSHOT/org.eclipse.jetty.jmx.ConnectorServerTest.testNoRegistryHostNonDefaultRegistryPort(ConnectorServerTest.java:97)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188)

How to reproduce?

cd jetty-core/jetty-jmx && mvn clean test -Dtest=ConnectorServerTest -Dmaven.build.cache.enabled=false

Also, the following Java program TestInetAddress.java:

import java.net.InetAddress;

public class TestInetAddress {
    public static void main(String[] args) throws Exception {
        InetAddress localHost = InetAddress.getLocalHost();
        InetAddress loopback = InetAddress.getLoopbackAddress();
        
        System.out.println("Local host: " + localHost + " (" + localHost.getHostAddress() + ")");
        System.out.println("Loopback: " + loopback + " (" + loopback.getHostAddress() + ")");
        System.out.println("Local host is loopback: " + localHost.isLoopbackAddress());
        System.out.println("Local host canonical name: " + localHost.getCanonicalHostName());
    }
}

Prints on macOS 15.5 (my dev Macbook):

Local host: mba.local/127.0.0.1 (127.0.0.1)
Loopback: localhost/127.0.0.1 (127.0.0.1)
Local host is loopback: true
Local host canonical name: localhost

Prints on Rocky Linux 8.10 (my server at Hetzner):

Local host: www/95.216.113.110 (95.216.113.110)
Loopback: localhost/127.0.0.1 (127.0.0.1)
Local host is loopback: false
Local host canonical name: www

Here are the logs (please wait for my upcoming PR):

ConnectorServerTest-fails.txt
ConnectorServerTest-fixed.txt

(The fixed log shows that the 3 tests has been fixed and only the unrelated testJMXOverTLS is still failing)