Firedrake meeting 2026 05 12

Date and time 2026-05-12 1600 UTC+1

Action Items

1. Pick Chair and Minuter (LC to pick -> PB)
2. ALL: (ongoing) triage the open issues and confirm if they are indeed still open (and perhaps provide labels)
3. ALL: do things with SV's branches
4. DH: Email to Andreas to have 2 (+ others!!!) loopy PRs merged TODO: FIND OUT WHICH PRS THESE ARE
5. DH: Talk to GregVernon about PR#2116.
6. CW: More testing configurations (minutes)
7. JHC: New manual release

Agenda

Present: PB, DH, CW, JHC, LC, IM

Apologies:

Team catch up

PB: Should we merge SubmeshHierarchy #5083 into release?

The main substance of the PR is SubmeshHierarchy, which is a very minor feature that does not break API.

We also added the first Submesh demo, demonstrating how to solve a very simple PDE with volume-surface coupling. The demo will be an excellent point of reference on how to deal with Measure intersection.

At least two users have asked about using multigrid + Submesh since the April release. Do we want to wait until the next release?

Conclusion: A change in merge policy, as we are rapidly evolving, we will start accepting new feature additions to be merged into release, as long as they are strictly additive.

PB: Related PR Fixes for multidomain form preprocessing #5089

Simple fix needed in order for Irksome + Submesh work out of the box.

Merged into release.

DH: we can set do_remove_component_tensors conditionally in release, and undonditionally in main. In that way we make sure that we don't cause different behaviour until the next relase.

CW: Testing configurations

We now have:

• Linux x86, Linux ARM, macOS
• real, complex
• single, double
• no GPU, CUDA
• int32, int64 (ideally)

I want to make sure that we can test them all thoroughly but without destroying our CI runners.

I propose:

• On every PR and push to release or main we run the full test suite for the 'default' configuration (Linux x86, real, double, no GPU)
• If a PR is marked ci:complex, ci:gpu, ci:macos, ci:single etc then we run the full test suite for that configuration, not just firedrake-check
• When we push to release or main we build every possible configuration and run a subset of the test suite. This subset will be more than firedrake-check and include any tests specific to that configuration (e.g. GPU+OffloadPC).

DH: too many combinations

CW: we will explicitly enumerate them and claim that we support them, but we only test a subset of these. We will allow for commuinity configuations, but not necessarily test them.

CW: we will only run certain subset of the test suite per configuation.

CW: Related PR

https://github.com/firedrakeproject/firedrake/pull/5099

CW: New manual release

Someone who isn't yet getting citations please do this :)

JHC: I will do it.

JHC & CW: petsctools.AppContext: https://github.com/firedrakeproject/petsctools/pull/16

Looking for feedback based on the demo.

DH: do things in the AppCtx die at the right time?

JHC: yes, we don't keep a handle of those things

Merge PRs

Date of next meeting

1600 UTC+0100 2026-05-19