If a user attempts to compile RHQ using the latest OpenJDK from the Fedora 11 repos, they'll run into the following compilation error when building the RHQ Network Services Plugin:

[INFO] ------------------------------------------------------------------------
[INFO] Building RHQ Network Services Plugin
[INFO]    task-segment: [install]
[INFO] ------------------------------------------------------------------------
[INFO] [build-helper:maven-version {execution: default}]
[INFO] [buildnumber:create {execution: default}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using default encoding to copy filtered resources.
[INFO] [dependency:copy {execution: copy-dependency-jars}]
[INFO] Configured Artifact: commons-httpclient:commons-httpclient:3.0.1:jar
[INFO] commons-httpclient:commons-httpclient:3.0.1:jar already exists in /home/thesteve04/workspace/rhq/modules/plugins/netservices/target/classes/lib
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Compiling 1 source file to /home/thesteve04/workspace/rhq/modules/plugins/netservices/target/classes
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure

could not parse error message: ----------
1. ERROR in /home/thesteve04/workspace/rhq/modules/plugins/netservices/src/main/java/org/rhq/plugins/netservices/PingNetServiceComponent.java (at line 75)
	return address.isReachable(5000) ? AvailabilityType.UP : AvailabilityType.DOWN;
	               ^^^^^^^^^^^

no more tokens - could not parse error message: The method isReachable(int) is undefined for the type InetAddress
----------
2. ERROR in /home/thesteve04/workspace/rhq/modules/plugins/netservices/src/main/java/org/rhq/plugins/netservices/PingNetServiceComponent.java (at line 93)
	address.isReachable(5000);
	        ^^^^^^^^^^^


[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.BuildFailureException: Compilation failure
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:715)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:556)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:535)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
   at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
   at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
   at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
   at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
   at java.lang.reflect.Method.invoke(libgcj.so.10)
   at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
   at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
   at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
   at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.plugin.CompilationFailureException: Compilation failure
   at org.apache.maven.plugin.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:516)
   at org.apache.maven.plugin.CompilerMojo.execute(CompilerMojo.java:114)
   at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
   at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
   ...14 more
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5 minutes 10 seconds
[INFO] Finished at: Fri Sep 11 14:56:50 GMT-04:00 2009
[INFO] Final Memory: 85M/122M
[INFO] ------------------------------------------------------------------------

From what ips is able to tell, it looks like this problem might stem from the fact that GNU Classpath does not currently implement the isReachable method in the InetAddress class at the moment, according to this document:  http://builder.classpath.org/japi/openjdk-classpath.html

For further information, here's a relevant IRC conversation:
<ssalevan> i could install the latest sun jdk, if worst comes to worst
<ips> another possible workaround would be to modify the build to not build the netservices plugin
<ips> you could do that by commenting out the netservices module in modules/plugins/pom.xml
<ssalevan> ips, hmm, that might work too
<ips> it will be good to find out if any other parts of the build fail w/ openjdk
<ips> then we can document it and maybe even setup the enforcer plugin to require sun jdk for those modules
<ssalevan> yeah...  would you be cool if i wrote up a bug on that?
<ssalevan> (it's qa instinct talking here)
<ips> sure, you could create an RHQ issue, and we can track this and any other compile errors you find 
<ips> we could then feed them back to the icedtea team and maybe they can get us some fixes