ImportError: cadquery was unable to determine freecad library path

Question

I am trying to run code from this source. The code is written in python 2, so I am using virtual environment with anaconda. The code replies on rather old versions of cadquery 1.2.0, which I installed into conda environment using pip. I also installed FreeCAD with the procedure described in the this page. When I ran the coed I get the following error:

ImportError: cadquery was unable to determine freecad library path

The full output is:

  File "generate_hilbert_curve.py", line 18, in <module>
    import cadquery as cq
  File "/Users/vid/opt/anaconda3/envs/python2/lib/python2.7/site-packages/cadquery/__init__.py", line 2, in <module>
    from .freecad_impl.geom import Plane,BoundBox,Vector,Matrix,sortWiresByBuildOrder
  File "/Users/vid/opt/anaconda3/envs/python2/lib/python2.7/site-packages/cadquery/freecad_impl/__init__.py", line 153, in <module>
    path = _fc_path()
  File "/Users/vid/opt/anaconda3/envs/python2/lib/python2.7/site-packages/cadquery/freecad_impl/__init__.py", line 145, in _fc_path
    raise ImportError('cadquery was unable to determine freecad library path')
ImportError: cadquery was unable to determine freecad library path

What are potential sources of error and possible solutions?