title: Cannot import rpy2.robjects after updating pandas "ValueError: The system "%s" is not supported."
body: <p>I'm running miniconda on Windows 10. I had installed rpy2 and used it in the past with no problems. Recently I upgraded from pandas version 0.24.0 to 0.25.1. After finding that broke a custom package that I've been working on I decided to drowngrade back to pandas version 0.24.0. After doing all that when I try to import robjects using the following:</p>
  
  <pre><code>import rpy2.robjects as ro
  </code></pre>
  
  <p>I get this error message:</p>
  
  <pre><code>---------------------------------------------------------------------------
  ValueError                                Traceback (most recent call last)
  &lt;ipython-input-5-d790458a85bf&gt; in &lt;module&gt;
  ----&gt; 1 import rpy2.robjects as ro
  
  C:\ProgramData\Miniconda3\lib\site-packages\rpy2\robjects\__init__.py in &lt;module&gt;
       12 import types
       13 import array
  ---&gt; 14 import rpy2.rinterface as rinterface
       15 import rpy2.rlike.container as rlc
       16 
  
  C:\ProgramData\Miniconda3\lib\site-packages\rpy2\rinterface.py in &lt;module&gt;
        4 import math
        5 import typing
  ----&gt; 6 from rpy2.rinterface_lib import openrlib
        7 import rpy2.rinterface_lib._rinterface_capi as _rinterface
        8 import rpy2.rinterface_lib.embedded as embedded
  
  C:\ProgramData\Miniconda3\lib\site-packages\rpy2\rinterface_lib\openrlib.py in &lt;module&gt;
       21 
       22 
  ---&gt; 23 rlib = _dlopen_rlib(R_HOME)
       24 
       25 
  
  C:\ProgramData\Miniconda3\lib\site-packages\rpy2\rinterface_lib\openrlib.py in _dlopen_rlib(r_home)
       16         raise ValueError('r_home is None. '
       17                          'Try python -m rpy2.situation')
  ---&gt; 18     lib_path = rpy2.situation.get_rlib_path(r_home, platform.system())
       19     rlib = ffi.dlopen(lib_path)
       20     return rlib
  
  C:\ProgramData\Miniconda3\lib\site-packages\rpy2\situation.py in get_rlib_path(r_home, system)
       70         lib_path = os.path.join(r_home, 'lib', 'libR.dylib')
       71     else:
  ---&gt; 72         raise ValueError('The system "%s" is not supported.')
       73     return lib_path
       74 
  
  ValueError: The system "%s" is not supported.
  </code></pre>