Logging improvements to Run related classes (#8777)

Logging improvements to Run related classes

core/src/main/java/hudson/model/Run.java

@@ -2480,10 +2480,12 @@ public EnvVars getEnvironment() throws IOException, InterruptedException {
         }
         Jenkins j = Jenkins.getInstanceOrNull();
         if (j == null) {
+            LOGGER.fine(() -> "Jenkins not running");
             return null;
         }
         Job<?, ?> job = j.getItemByFullName(jobName, Job.class);
         if (job == null) {
+            LOGGER.fine(() -> "no such job " + jobName + " when running as " + Jenkins.getAuthentication2().getName());
             return null;
         }
         return job.getBuildByNumber(number);

core/src/main/java/hudson/model/RunMap.java

@@ -239,6 +239,7 @@ protected R retrieve(File d) throws IOException {
                 LOGGER.log(Level.WARNING, "could not load " + d, e);
             }
         }
+        LOGGER.fine(() -> "no config.xml in " + d);
         return null;
     }
 

core/src/main/java/jenkins/model/lazy/AbstractLazyLoadRunMap.java

@@ -518,15 +518,21 @@ public R getByNumber(int n) {
         Index snapshot = index;
         if (snapshot.byNumber.containsKey(n)) {
             BuildReference<R> ref = snapshot.byNumber.get(n);
-            if (ref == null)      return null;    // known failure
+            if (ref == null) {
+                LOGGER.fine(() -> "known failure of #" + n + " in " + dir);
+                return null;
+            }
             R v = unwrap(ref);
-            if (v != null)        return v;       // already in memory
+            if (v != null) {
+                return v; // already in memory
+            }
             // otherwise fall through to load
         }
         synchronized (this) {
             if (index.byNumber.containsKey(n)) { // JENKINS-22767: recheck inside lock
                 BuildReference<R> ref = index.byNumber.get(n);
                 if (ref == null) {
+                    LOGGER.fine(() -> "known failure of #" + n + " in " + dir);
                     return null;
                 }
                 R v = unwrap(ref);
@@ -655,7 +661,10 @@ private R load(File dataDir, Index editInPlace) {
         assert Thread.holdsLock(this);
         try {
             R r = retrieve(dataDir);
-            if (r == null)    return null;
+            if (r == null) {
+                LOGGER.fine(() -> "nothing in " + dataDir);
+                return null;
+            }
 
             Index copy = editInPlace != null ? editInPlace : new Index(index);