Found it!

dwarf-bug.log

>>> n
YOU HAVE CRAWLED AROUND IN SOME LITTLE HOLES AND WOUND UP BACK IN THE
MAIN PASSAGE.

THERE IS A THREATENING LITTLE DWARF IN THE ROOM WITH YOU!

YOU'RE AT WITT'S END.

>>> pp(w.game.objects_here)
[]
>>> w.game.inventory
[<Object 2 lamp/headlamp/lantern 7f680c27ea58>, <Object 4 cage 7f680c27ec88>, <Object 8 bird 7f680c27ef28>, <Object 16 magazine/issue/spelunker/"spel 7f680c283470>, <Object 28 axe 7f680c283e10>, <Object 52 silver/bars 7f680c288780>]
>>> take(dwarf)
OK

>>> w.game.objects_here
[]
>>> w.game.inventory
[<Object 2 lamp/headlamp/lantern 7f680c27ea58>, <Object 4 cage 7f680c27ec88>, <Object 8 bird 7f680c27ef28>, <Object 16 magazine/issue/spelunker/"spel 7f680c283470>, <Object 17 dwarf/dwarves 7f680c283550>, <Object 28 axe 7f680c283e10>, <Object 52 silver/bars 7f680c288780>]
>>> drop(dwarf)
OK

>>> w.game.objects_here
[<Object 17 dwarf/dwarves 7f680c283550>]
>>> w.game.objects_here.prop
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'list' object has no attribute 'prop'
>>> w.game.objects_here[0]
<Object 17 dwarf/dwarves 7f680c283550>
>>> w.game.objects_here[0].prop
0
>>> w.game.objects_here[0].messages
{}
>>> d
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/prompt.py", line 18, in __repr__
    output = self.game.do_command(self.words)
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 437, in do_command
    self._do_command(words)
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 506, in _do_command
    self.dispatch_command(words)
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 553, in dispatch_command
    return self.do_motion(word1)
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 706, in do_motion
    self.move_to()
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 186, in move_to
    self.move_dwarves()
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 325, in move_dwarves
    self.describe_location()
  File "/bb/mbigd/mbig6213/personal/python-adventure/adventure/game.py", line 379, in describe_location
    self.write(obj.messages[prop])
KeyError: 0