[HUDSON-3984] Added logging.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@19719 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/util/ProcessTree.java

@@ -418,7 +418,9 @@ public abstract class ProcessTree implements Iterable<OSProcess> {
          */
         public void kill() {
             try {
-                UnixReflection.DESTROY_PROCESS.invoke(null,getPid());
+                int pid = getPid();
+                LOGGER.fine("Killing pid="+pid);
+                UnixReflection.DESTROY_PROCESS.invoke(null, pid);
             } catch (IllegalAccessException e) {
                 // this is impossible
                 IllegalAccessError x = new IllegalAccessError();