I just set the environment variables in the shell before I ran the conda env update command. I don’t think you’d want to set those globally. Actually, just this morning I went back to see if I could make it work from scratch and found that I must have installed fiona (from conda-forge) before updating the environment:
conda install -c conda-forge fiona
Or, you could just add the line under dependencies in the environment.yml file:
- conda-forge::fiona>=1.7.13
And then just a single conda env update should work.