Log information about the baseline and new View passed to DiffAwarness#getDiff.

--
MOS_MIGRATED_REVID=98382658

2 files changed, 8 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
index 2248607c0b..f57ec0d845 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
@@ -103,6 +103,7 @@ public final class DiffAwarenessManager {
     }
 
     ModifiedFileSet diff;
+    LOG.info("About to compute diff between " + baselineView + " and " + newView);
     try {
       diff = diffAwareness.getDiff(baselineView, newView);
     } catch (BrokenDiffAwarenessException e) {
@@ -119,6 +120,7 @@ public final class DiffAwarenessManager {
 
   private void handleBrokenDiffAwareness(Path pathEntry, BrokenDiffAwarenessException e) {
     currentDiffAwarenessStates.remove(pathEntry);
+    LOG.info("Broken diff awareness for " + pathEntry + ": " + e);
     reporter.handle(Event.warn(e.getMessage() + "... temporarily falling back to manually "
         + "checking files for changes"));
   }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java b/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
index 389f39a638..dba00768ce 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
@@ -114,6 +114,12 @@ public class LocalDiffAwareness implements DiffAwareness {
     public static boolean areInSequence(SequentialView oldView, SequentialView newView) {
       return oldView.owner == newView.owner && (oldView.position + 1) == newView.position;
     }
+
+    @Override
+    public String toString() {
+      return String.format("SequentialView[owner=%s, position=%d, modifiedAbsolutePaths=%s]", owner,
+          position, modifiedAbsolutePaths);
+    }
   }
 
   @Override