Issue importing proplot #454

In [1]: import proplot
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[1], line 1
----> 1 import proplot

File ~/anaconda3/envs/cf3/lib/python3.9/site-packages/proplot/__init__.py:38
     36     from .colors import *  # noqa: F401 F403
     37 with _benchmark('ticker'):
---> 38     from .ticker import *  # noqa: F401 F403
     39 with _benchmark('scale'):
     40     from .scale import *  # noqa: F401 F403

File ~/anaconda3/envs/cf3/lib/python3.9/site-packages/proplot/ticker.py:18
     16 try:
     17     import cartopy.crs as ccrs
---> 18     from cartopy.mpl.ticker import (
     19         _PlateCarreeFormatter, LatitudeFormatter, LongitudeFormatter
     20     )
     21 except ModuleNotFoundError:
     22     ccrs = None

File ~/anaconda3/envs/cf3/lib/python3.9/site-packages/cartopy/mpl/ticker.py:13
     10 import numpy as np
     12 import cartopy.crs as ccrs
---> 13 from cartopy.mpl.geoaxes import GeoAxes
     16 class _PlateCarreeFormatter(Formatter):
     17     """
     18     Base class for formatting ticks on geographical axes using a
     19     rectangular projection (e.g. Plate Carree, Mercator).
     20 
     21     """

File ~/anaconda3/envs/cf3/lib/python3.9/site-packages/cartopy/mpl/geoaxes.py:43
     41 import cartopy.mpl.contour
     42 import cartopy.mpl.feature_artist as feature_artist
---> 43 import cartopy.mpl.geocollection
     44 import cartopy.mpl.patch as cpatch
     45 from cartopy.mpl.slippy_image_artist import SlippyImageArtist

File ~/anaconda3/envs/cf3/lib/python3.9/site-packages/cartopy/mpl/geocollection.py:13
      9 import numpy.ma as ma
     10 import packaging
---> 13 _MPL_VERSION = packaging.version.parse(mpl.__version__)
     16 def _split_wrapped_mesh_data(C, mask):
     17     """
     18     Helper function for splitting GeoQuadMesh array values between the
     19     pcolormesh and pcolor objects when wrapping.  Apply a mask to the grid
     20     cells that should not be plotted with each method.
     21 
     22     """

AttributeError: module 'packaging' has no attribute 'version'