This started showing up recently in the nova unit tests:
Exception nova.virt.vmwareapi.error_util.VimFaultException: VimFaultException() in <bound method VMwareAPISession.__del__ of <nova.virt.vmwareapi.driver.VMwareAPISession object at 0x11bb66cc>> ignored
Exception nova.virt.vmwareapi.error_util.VimFaultException: VimFaultException() in <bound method VMwareAPISession.__del__ of <nova.virt.vmwareapi.driver.VMwareAPISession object at 0x127d868c>> ignored
Exception nova.virt.vmwareapi.error_util.VimFaultException: VimFaultException() in <bound method VMwareAPISession.__del__ of <nova.virt.vmwareapi.driver.VMwareAPISession object at 0x118b390c>> ignored
It doesn't cause a failure, but it's ugly and should be cleaned up.
Looks like the destructor is throwing something from the Logout method. That's probably something trivial to fix.