Update HPC module templates that load Python < 3.10 (Bridges2, Expanse, Richardson, Ascent)

[sbryngelson]

Problem

toolchain/bootstrap/python.sh has enforced a Python ≥ 3.10 minimum since before the viz PR:

MFC_PYTHON_MIN_MAJOR=3
MFC_PYTHON_MIN_MINOR=10

./mfc.sh build calls this script early and exits with a clear error if the active Python is older. The pyproject.toml requires-python = ">=3.10" field formalises the same constraint.

However, several entries in toolchain/modules still load Python versions below 3.10. Any user who runs source ./mfc.sh load -c <slug> -m <mode> on these systems and then runs ./mfc.sh build will hit the following error immediately:

error: Python 3.x.y (python3) is out of date. Required >= 3.10.

Affected systems

Slug	System	Module loaded	Version	Status
b	PSC Bridges2	python/3.8.6	3.8.6	❌
e	SDSC Expanse	python/3.8.5	3.8.5	❌
r	Richardson	python/3.7	3.7	❌
a	OLCF Ascent	python (no version pinned)	unknown	⚠️ check default

Systems already loading Python ≥ 3.10 (no change needed):
p (3.12.5), tuo (3.12.2), w (3.10.8), c (3.12.1), cc (cray-python/3.11.7), o (3.13), h (3.12), f/famd/d/dai/san (unversioned python — verify defaults are ≥ 3.10).

Required changes to toolchain/modules

Each affected entry needs to be updated to a Python 3.10+ module that the cluster actually provides. The relevant maintainer for each cluster should verify available versions via module spider python and update the entry.

PSC Bridges2 (b)

-b-all python/3.8.6 hdf5 anaconda3
+b-all python/3.11.x hdf5 anaconda3   # verify available version

Bridges2 ships Python 3.11 via module load python/3.11.x (check with module spider python). If no 3.10+ module exists, the fallback is to use the anaconda3 module and conda activate an environment with Python 3.10+.

SDSC Expanse (e)

-e-all python/3.8.5
+e-all python/3.10.x   # or 3.11/3.12 — check module spider

Expanse provides newer Python via module spider python. As of 2024, Python 3.11 modules are available.

Richardson (r)

-r-all python/3.7
+r-all python/3.10.x   # verify available

This system may be decommissioned or may only have old Python available — if no 3.10+ module exists the entry should be removed or documented as unsupported.

OLCF Ascent (a)

The entry loads python without a version pin. Verify that the default Python module on Ascent is ≥ 3.10, and pin it if possible:

-a-all python cmake/3.22.2
+a-all python/3.x.y cmake/3.22.2   # pin to confirmed 3.10+ version

How to verify

After updating an entry, test end-to-end on the cluster:

source ./mfc.sh load -c <slug> -m c
python3 --version          # must be >= 3.10
./mfc.sh build -j 8

Why Python 3.10?

bootstrap/python.sh has required 3.10 for some time — this is not a new constraint introduced by the viz subcommand. The viz subcommand does use some dependencies (textual) that themselves require 3.8+, so the binding constraint remains the toolchain bootstrap script. Python 3.10 added structural pattern matching and improved type annotation syntax used elsewhere in the toolchain.

Notes

• If a cluster genuinely has no Python 3.10+ module, the workaround is to install miniconda in the user's home directory and conda activate an environment before running ./mfc.sh. This should be documented in the entry as a comment.
• Unversioned python entries (a, d, dai, f, famd, san) should be audited to confirm their default is ≥ 3.10, and pinned to a specific version where possible to prevent silent regressions when cluster admins update the default.