Traceback (most recent call last):
  File "/nix/store/3b0aw9v4z4ykb4yl0ns73clqg9wkys0f-python3.9-nix-gui-0.1.0/lib/python3.9/site-packages/nixui/graphics/navbar.py", line 49, in <lambda>
    back_btn.clicked.connect(lambda: set_lookup_key_fn(None))
  File "/nix/store/3b0aw9v4z4ykb4yl0ns73clqg9wkys0f-python3.9-nix-gui-0.1.0/lib/python3.9/site-packages/nixui/graphics/nav_interface.py", line 52, in set_lookup_key
    return self.revert_to_previous_lookup_key()
  File "/nix/store/3b0aw9v4z4ykb4yl0ns73clqg9wkys0f-python3.9-nix-gui-0.1.0/lib/python3.9/site-packages/nixui/graphics/nav_interface.py", line 43, in revert_to_previous_lookup_key
    previous_uri = self.uri_stack.pop()
IndexError: pop from an empty deque