Debug silent exception source.

vars/getVolthaCode.groovy
-------------------------
  o Report branch being checked out while cloning voltha-helm-charts
    and voltha-system-tests.  For release, if repos have not been
    branched already a voltha repsository job will fail with cryptic err:
       "Couldn't find any revision to build"

Change-Id: Iea5bd516e17cd6831305ff860c9378b0c61e5edd
diff --git a/vars/getVolthaCode.groovy b/vars/getVolthaCode.groovy
index a6a40fb..23b373d 100644
--- a/vars/getVolthaCode.groovy
+++ b/vars/getVolthaCode.groovy
@@ -118,7 +118,7 @@
     // -----------------------------------------------------------------------
     stage('Clone voltha-system-tests')
     {
-        enter('Clone voltha-system-tests')
+        enter("Clone voltha-system-tests @ BRANCH=[${cfg.branch}]")
         println("""
 
 ** -----------------------------------------------------------------------
@@ -162,14 +162,14 @@
             leave("git fetch https://${cfg.gerritProject}")
         }
 
-        leave('Clone voltha-system-tests')
+        leave("Clone voltha-system-tests @ BRANCH=[${cfg.branch}]")
     }
 
     // -----------------------------------------------------------------------
     // -----------------------------------------------------------------------
     stage('Clone voltha-helm-charts')
     {
-        enter('Clone voltha-helm-charts')
+        enter("Clone voltha-helm-charts @ BRANCH=[${cfg.branch}]")
         repo_vhc = 'https://gerrit.opencord.org/voltha-helm-charts'
 
         checkout([
@@ -204,7 +204,7 @@
             leave('cfg.gerritProject == voltha-helm-charts')
         }
 
-        leave('Clone voltha-helm-charts')
+        leave("Clone voltha-helm-charts @ BRANCH=[${cfg.branch}]")
     }
 }