It is important to have the exactly same versions on both computers. For performance reasons, it is recommended to use software from the modules as much as possible. Because modules tend to lag slightly behind the latest versions, one should first create a virtual environment on snellius, and then derive the requirements for the environment on the RA based on this.

The following procedure allows to do this.

0. Access a regular snellius node.

1. Define software to load from snellius with module load XYZ in modules.sh. Try to have as much software as possible in this file.

2. Add more packages to pip_requirements.

3. Run

   bash ossc/build_requirements.sh

   This command

   • loads all modules
   • creates a virtual environment and installs more packages from pip
   • exports the exact requirements from this venv to the file defined in OSSC_requirements
   • translates these requirements to a "regular" requirements.txt file, defined by RA_requirements.
   • compares these requirements to the environment0000.txt defined in the repository root. (Most people can probably ignore this.)

4. Try to create the regular venv as follows

   declare PYTHON_VERSION=3.11.3 # this should match the Python module version from snellius
   declare RA_requirements="ossc/environment0000.txt" # match the same variable in modules.sh
   
   pyenv local "$PYTHON_VERSION"
   python -m venv .venv
   source .venv/bin/activate
   pip install -r "$RA_requirements"

   If this works continue to 6. Otherwise, continue with 5.

5. Iterate steps 1-4 by finding the right dependency versions. I found that moving software from modules.sh to pip_requirements.txt can help resolve dependencies.

6. Follow CBS instructions to install environment0000.txt

7. Give OSSC_requirements and modules.sh to SURF for installation on the OSSC.

After SURF has installed the environment -- say it's stored under ossc_env/ --, you should be able to use it as follows

#!/bin/bash
source modules.sh
source ossc_env/bin/activate