Error using to_crs() -- no such file or directory - ONLY on windows

Hi Colleagues. Some of my students are running into errors when they reproject using this code:

object.to_crs(another_object.crs)

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-5-eb6d1da3880a> in <module>()
----> 1 sjer_aoi_wgs84  = sjer_aoi.to_crs(sjer_roads.crs)

~\Anaconda3\envs\earth-analytics-python\lib\site-packages\geopandas\geodataframe.py in to_crs(self, crs, epsg, inplace)
    441         else:
    442             df = self.copy()
--> 443         geom = df.geometry.to_crs(crs=crs, epsg=epsg)
    444         df.geometry = geom
    445         df.crs = geom.crs

~\Anaconda3\envs\earth-analytics-python\lib\site-packages\geopandas\geoseries.py in to_crs(self, crs, epsg)
    302             except TypeError:
    303                 raise TypeError('Must set either crs or epsg for output.')
--> 304         proj_in = pyproj.Proj(self.crs, preserve_units=True)
    305         proj_out = pyproj.Proj(crs, preserve_units=True)
    306         project = partial(pyproj.transform, proj_in, proj_out)

~\Anaconda3\envs\earth-analytics-python\lib\site-packages\pyproj\__init__.py in __new__(self, projparams, preserve_units, **kwargs)
    356         # on case-insensitive filesystems).
    357         projstring = projstring.replace('EPSG','epsg')
--> 358         return _proj.Proj.__new__(self, projstring)
    359 
    360     def __call__(self, *args, **kw):

_proj.pyx in _proj.Proj.__cinit__()

RuntimeError: b'No such file or directory'

i have not been able to recreate it on my mac but can on windows 10. I found this issue which looks related: https://github.com/jswhit/pyproj/issues/101

and this SE post

https://gis.stackexchange.com/questions/295914/error-in-coordinate-transformation-with-geopandas

to which @jorisvandenbossche suggested removing proj4 and pyproj. i tried that but it did not fix the issue. also when you remove proj4 you have to remove gdal and rasterio and cartopy… so all of a sudden my environment is gone. I also did a full fresh reinstall of the environment.

Any ideas how I can resolve this issue? And why is it so windows specific!? note - i’m on a pretty fresh windows install and do not have arcgis or anything else here. just git, python / conda and a few other basic tools for text editins and such. im using python 3.x.

Many thanks for any suggestions.

[gboeing]

On my machines I got it working via:

import os
os.environ["PROJ_LIB"] = "C:\Anaconda\envs\env_name\Library\share" #windows
os.environ["PROJ_LIB"] = ".../Anaconda/envs/env_name/Library/share" #linux

[jtamerius]

On my machines I got it working via:

import os
os.environ["PROJ_LIB"] = "C:\Anaconda\envs\env_name\Library\share" #windows
os.environ["PROJ_LIB"] = ".../Anaconda/envs/env_name/Library/share" #linux

This worked for me. Thanks @gboeing !