pip does not install new version

[kdolum]

I'm trying to install the current code (ba5c332) in a new conda environment. In my environment.yml file I put

 - pip:
    - git+https://github.com/vallis/libstempo

But this did not work. It gave me the old version that gives the error about units support. So I removed it with conda uninstall --force libstempo, and installed it directly with pip install git+https://github.com/vallis/libstempo. This did work. Both versions are reported by pip list as version 2.4.6, which I found confusing. Specifying @ba5c332 does not change anything. It does not work to install it with pip after having already included it in the conda install. So I guess that pip thinks that somehow these are the same version and so it doesn't need to actually install the new version when the old one is installed already. Is this a packaging problem or am I not using pip correctly? Thanks.