Extra debug output in test.
Extra debug output in test.

Fix a debug output for a failing case and add the stack trace details as
we have it.

Change-Id: I634c1743a7714a661d23905eccbd5044e48487e6

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst