_libsol not found python 3.8.3 Windows 10

[ms03831]

pysbol version: 2.3.3.post8, Python 3.8.3 on Windows 10.
Installed pysbol using source on GitHub, compiled using python setup.py install which produced the sbol package inside an egg file in site-packages.
$import sbol
leads to this error:
return _bootstrap._gcd_import(name[level:], package, level)
ModuleNotFoundError: No module named '_libsbol'

Before trying this, I had Python 3.7.3 and no matter what I tried pip installing would install pysbol 2.3.2.post5. pysbol worked in that case well except that I had this issue. The same configuration (python 3.8.3 and pysbol) works well on Mac.