$ ./result/bin/rio
proj_create: init=epsg:/init=IGNF: syntax not supported in non-PROJ4 emulation mode
Traceback (most recent call last):
  File "/nix/store/ffv9d9pifmip3x24ymxf4nkdfw7jggsl-python3.7-rasterio-1.0.28/bin/.rio-wrapped", line 7, in <module>
    from rasterio.rio.main import main_group
  File "/nix/store/ffv9d9pifmip3x24ymxf4nkdfw7jggsl-python3.7-rasterio-1.0.28/lib/python3.7/site-packages/rasterio/rio/main.py", line 35, in <module>
    from pkg_resources import iter_entry_points
ModuleNotFoundError: No module named 'pkg_resources'

$ ./result/bin/rio --help
proj_create: init=epsg:/init=IGNF: syntax not supported in non-PROJ4 emulation mode
Usage: rio [OPTIONS] COMMAND [ARGS]...

  Rasterio command line interface.
...