Add more logs on bad manifests

Change-Id: Ifa43108238ffa916c068cd686bf7632c89f05068
diff --git a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/Utilities.java b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/Utilities.java
index 68e80e4..73dcddc 100644
--- a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/Utilities.java
+++ b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/Utilities.java
@@ -134,7 +134,9 @@
                                     commit.getId(), null);
       return commit.getId();
     } else {
-      log.warn("Failing to commit manifest subscription update");
+      log.warn("Failing to commit manifest subscription update:"+
+               "\n\tProject: " + projectName +
+               "\n\tRef: " + refName);
     }
 
     return null;
diff --git a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
index 6f7b7d3..0e87269 100644
--- a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
+++ b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
@@ -332,10 +332,10 @@
           try (Repository db = gitRepoManager.openRepository(p)) {
             hash = db.resolve(ref).getName();
           } catch (IOException | NullPointerException e) {
-            log.warn(ref);
-            log.warn(projectName);
-            log.warn(defaultRef);
-            e.printStackTrace();
+            log.warn("Cannot resolve ref: " + ref +
+                "\n\t" + projectName +
+                "\n\t" + defaultRef +
+                "\n\t" + Arrays.toString(e.getStackTrace()));
           }
         }