similar bug found with dead eventlet runloop. a greenthread doesn't get its parent set to new hub greenlet unless switching back to the hub. If it dies before then it'll return execution to dead hub greenlet.

eventlet_dead_runloop_bug2.py

import eventlet


def dummyproc():
    print 'dummyproc returning. but our parent is *old, dead* hub greenlet'

eventlet.sleep(0)  # give hub a chance to run
g = eventlet.spawn(dummyproc)
print 'killing hub before spawned greenthread timer is run'
try:
    # use throw() method on greenlet rather
    # than eventlet.greenthread.kill()
    eventlet.hubs.get_hub().greenlet.throw(KeyboardInterrupt())
except KeyboardInterrupt:
    pass
print 'killed hub. switching back to create new runloop greenlet'
eventlet.hubs.get_hub().switch()
print 'should not get here!'