Set QUARTO_PYTHON, see rocker-org/rocker-versioned2#860 (comment), close geocompx#107

Author: Robinlovelace

rocker-rpy/Dockerfile

@@ -10,6 +10,8 @@ ENV PATH=/opt/venv/bin:${PATH}
 
 # Override the python symlink to use the venv Python (not system Python)
 RUN ln -sf /opt/venv/bin/python /usr/bin/python
+# Set version of Python that Quarto will use:
+ENV QUARTO_PYTHON=/opt/venv/bin/python
 
 # Optionally install project requirements into the existing venv if desired:
 RUN /opt/venv/bin/pip install -r https://github.com/geocompx/geocompy/raw/refs/heads/main/requirements.txt