trying a different hack

Dockerfile

@@ -27,9 +27,7 @@ RUN conda env create -n ${CONDA_ENV} -f requirements.yml
 
 # Shrink conda environment into portable non-conda env
 RUN conda install conda-pack -c conda-forge
-# Hack to get zstandard from PyPI - remove if conda-forge linked lib issue is resolved
-RUN conda run -n ${CONDA_ENV} pip uninstall zstandard -y \
-  && conda run -n ${CONDA_ENV} pip install --no-cache-dir --no-deps zstandard==0.21.0
+
 RUN conda-pack -n ${CONDA_ENV} --ignore-missing-files -o /tmp/env.tar \
   && mkdir -p /app/venv \
   && cd /app/venv \
@@ -63,6 +61,8 @@ COPY --from=bigtable-emulator-build /go/bin/emulator /app/venv/bin/cbtemulator
 COPY override/gcloud /app/venv/bin/gcloud
 COPY override/timeout.conf /etc/nginx/conf.d/timeout.conf
 COPY override/supervisord.conf /etc/supervisor/conf.d/supervisord.conf
+# Hack to get zstandard from PyPI - remove if conda-forge linked lib issue is resolved
+RUN  pip install --no-cache-dir --no-deps --force-reinstall zstandard==0.21.0
 COPY . /app
 
 RUN mkdir -p /home/nginx/.cloudvolume/secrets \