Add support for Intel ifx 2025.3 (oneAPI Fortran Compiler)

[zbeekman]

Summary

Intel released Fortran Compiler 2025.3 (latest patch: 2025.3.2) on Linux and Windows, but setup-fortran currently caps at 2025.2.

Current state

.github/compat/latest-versions.sh:

LATEST_intel_ubuntu_22_04="2025.2"
LATEST_intel_ubuntu_24_04="2025.2"
LATEST_intel_windows_2022="2025.2"
LATEST_intel_windows_2025="2025.2"

README compatibility table shows 2025.2 as max for intel (ifx) on all supported Linux/Windows runners.

Requested change

Add 2025.3 (and/or 2025.3.2 patch) for:

• ubuntu-22.04
• ubuntu-24.04
• windows-2022
• windows-2025

Upstream references

• Intel announcement (2025.3.2 with VS 2026 support): https://community.intel.com/t5/Intel-Fortran-Compiler/Intel-Fortran-Compiler-2025-3-2-is-available-with-Microsoft/td-p/1735901
• Intel oneAPI Fortran release notes: https://www.intel.com/content/www/us/en/developer/articles/release-notes/fortran-compiler/2025.html

Files that likely need update

For whoever picks this up (possibly me, possibly not -- depends on bandwidth):

• .github/compat/compat.csv -- source-of-truth: add 2025.3 column under intel, mark ✓ for ubuntu-22.04, ubuntu-24.04, windows-2022, windows-2025
• .github/compat/latest-versions.sh -- auto-regenerated via update_latest_versions.py (header says don't hand-edit)
• setup-fortran.sh:
  • Version normalization case block (~L514-531) -- add 2025.3 | 2025.3.2) arm alongside existing 2025.2 | 2025.2.1)
  • Linux apt resolved-version case (~L609-620) -- same pattern
  • Windows installer URL block (~L755+) -- new WINDOWS_HPCKIT_URL for 2025.3 offline installer (need actual URL from Intel registration center) plus WINDOWS_HPCKIT_COMPONENTS
• .github/workflows/test.yml -- test matrix is dynamically generated from compat data, so likely picks up automatically; worth confirming after CSV update
• README.md -- compat table (verify whether auto-regenerated alongside latest-versions.sh)

install-intel-windows.bat looks generic (URL via %1), so no change there.

Maintainers:

• Do these touch points look right, or am I missing anything?
• Are you aware of any other issue blocking implementing this?

Flagging now so it's tracked; may circle back with a PR if I get to it before someone else.

[wpbonelli]

Thanks. New intel versions are more annoying to add than the other toolchains. You mostly got it except matrix.yml also needs editing.

It's like this, there are 2 CI modes: report and assert. PR trigger runs assert mode, manual trigger runs report mode. Assert mode reads the CSVs and makes sure the combos work. Report mode reads the matrix, tests all the combos, and generates the CSVs/README to reflect what works. The matrix.yml is the source of truth about what we want, the CSVs are the source of truth about which subset of it we get.

It's a chicken/egg situation though, there's no easy way to test new entries without adding them to the CSVs. I usually hand-edit one entry in per new or modified code path, let actions test it, then revert the CSVs, merge, and let actions regenerate them and the readme. Occasionally we get false failures from report mode due to broken network or 3rd party endpoints so I usually run report mode a few times and check consistency before merging the CSV/readme update.

I will make a DEVELOPER.md or CONTRIBUTING.md describing all this. If you see a better way to do anything, suggestions very welcome