Traceback (most recent call last):


 "/Users/igortkachenko/Tools/kivy-designer/venv/lib/python3.6/site-packages/kivy/uix/widget.py", line 265, in _widget_destructor


 "/Users/igortkachenko/Tools/kivy-designer/venv/lib/python3.6/site-packages/kivy/lang/builder.py", line 760, in unbind_widget


 "kivy/weakproxy.pyx", line 30, in kivy.weakproxy.WeakProxy.__getattr__
AttributeError: 'weakref' object has no attribute 'cline_in_traceback'

$ pip install --upgrade pTraceback (most recent call last):


 "/usr/local/bin/pip3", line 11, in <module>

sys.exit(main())


 "/usr/local/lib/python3.7/site-packages/pip/_internal/__init__.py", line 293, in main

autocomplete()


 "/usr/local/lib/python3.7/site-packages/pip/_internal/__init__.py", line 121, in autocomplete

cwords, cword, subcommand.parser.option_list_all,


 "/usr/local/lib/python3.7/site-packages/pip/_internal/__init__.py", line 170, in get_path_completion_type

for x in opt.metavar.split('/')):
AttributeError: 'NoneType' object has no attribute 'split'
