[JENKINS-22395] Yet more diagnostics.

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

@@ -435,7 +435,7 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
         // result can only get worse
         if (result==null || r.isWorseThan(result)) {
             result = r;
-            LOGGER.log(FINE, this + " : result is set to " + r, LOGGER.isLoggable(Level.FINER) ? new Exception() : null);
+            LOGGER.log(FINE, this + " in " + getRootDir() + ": result is set to " + r, LOGGER.isLoggable(Level.FINER) ? new Exception() : null);
         }
     }
 
@@ -1451,7 +1451,7 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
     public void delete() throws IOException {
         File rootDir = getRootDir();
         if (!rootDir.isDirectory()) {
-            throw new IOException(this + ": " + rootDir + " looks to have already been deleted");
+            throw new IOException(this + ": " + rootDir + " looks to have already been deleted; siblings: " + Arrays.toString(project.getBuildDir().list()));
         }
         
         RunListener.fireDeleted(this);

core/src/main/java/hudson/tasks/LogRotator.java

@@ -108,7 +108,7 @@ public class LogRotator extends BuildDiscarder {
 
     @SuppressWarnings("rawtypes")
     public void perform(Job<?,?> job) throws IOException, InterruptedException {
-        LOGGER.log(FINE, "Running the log rotation for {0}", job);
+        LOGGER.log(FINE, "Running the log rotation for {0} with numToKeep={1} daysToKeep={2} artifactNumToKeep={3} artifactDaysToKeep={4}", new Object[] {job, numToKeep, daysToKeep, artifactNumToKeep, artifactDaysToKeep});
         
         // always keep the last successful and the last stable builds
         Run lsb = job.getLastSuccessfulBuild();

core/src/main/java/jenkins/model/StandardArtifactManager.java

@@ -32,6 +32,8 @@ import hudson.model.Run;
 import java.io.File;
 import java.io.IOException;
 import java.util.Map;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import jenkins.util.VirtualFile;
 
 /**
@@ -41,6 +43,8 @@ import jenkins.util.VirtualFile;
  */
 public class StandardArtifactManager extends ArtifactManager {
 
+    private static final Logger LOG = Logger.getLogger(StandardArtifactManager.class.getName());
+
     protected transient Run<?,?> build;
 
     public StandardArtifactManager(Run<?,?> build) {
@@ -60,8 +64,10 @@ public class StandardArtifactManager extends ArtifactManager {
     @Override public final boolean delete() throws IOException, InterruptedException {
         File ad = getArtifactsDir();
         if (!ad.exists()) {
+            LOG.log(Level.FINE, "no such directory {0} to delete for {1}", new Object[] {ad, build});
             return false;
         }
+        LOG.log(Level.FINE, "deleting {0} for {1}", new Object[] {ad, build});
         Util.deleteRecursive(ad);
         return true;
     }