CORD-2951 clean-all during post build

Change-Id: I3368541f7a3b5c9324219cd1fdd18feda66ace3f
diff --git a/Jenkinsfile.newBuildSystem b/Jenkinsfile.newBuildSystem
index 455b0b3..8380642 100644
--- a/Jenkinsfile.newBuildSystem
+++ b/Jenkinsfile.newBuildSystem
@@ -273,6 +273,9 @@
         } catch (err) {
             currentBuild.result = 'FAILURE'
             step([$class: 'Mailer', notifyEveryUnstableBuild: true, recipients: "${notificationEmail}", sendToIndividuals: false])
+        } finally {
+            sh "make -C build clean-all || true"
+            sh "rm -rf *"
         }
         echo "RESULT: ${currentBuild.result}"
     }