Correct CMAKE_BUILD_TYPE in end user Docker images

[jorgensd]

Related to the nightly timings #2891.
We still have a regression with the introduction of nanobind, but now we are down to a halving in performance.

[jhale]

I would propose we remove DOLFINX_CMAKE_CXX_FLAGS=-O2 as RelWithDebInfo is usually picked as -O2 -g -DNDEBUG anyway.

Perhaps we should go for Release on these images, that typically enables -O3. How useful really is the DebugInfo for users?

Edit: I'm thinking the tagged versions e.g. :v0.7.2 should be done with Release, and :nightly should have RelWithDebInfo. It's not urgent, let's switch to RelWithDebInfo as you suggest for now.

[jhale]

We can discuss the nanobind performance issues separately.

[jorgensd]

I would propose we remove DOLFINX_CMAKE_CXX_FLAGS=-O2 as RelWithDebInfo is usually picked as -O2 -g -DNDEBUG anyway.

Perhaps we should go for Release on these images, that typically enables -O3. How useful really is the DebugInfo for users?

Edit: I'm thinking the tagged versions e.g. :v0.7.2 should be done with Release, and :nightly should have RelWithDebInfo. It's not urgent, let's switch to RelWithDebInfo as you suggest for now.

Agreed, this is a separate issue. It is mostly important to get some better performance on the nightly images.

[michalhabera]

Remove CMAKE_CXX_FLAGS, it does not work anyway because --config-settings=cmake.define.-DCMAKE_CXX_FLAGS is wrong and should be --config-settings=cmake.define.CMAKE_CXX_FLAGS. Moreover, build type overwrites these, so we'd need --config-settings=cmake.define.CMAKE_CXX_FLAGS_RELEASE for Release build etc.

[francesco-ballarin]

Once we are done with the change proposed by @michalhabera , can @jorgensd manually trigger https://github.com/FEniCS/dolfinx/actions/workflows/docker-end-user.yml ?
After the nightly image is manually rebuilt, I'll trigger a handful of runs in the multiphenicsx repo to see if it is still affected by #2884

[jorgensd]

Once we are done with the change proposed by @michalhabera , can @jorgensd manually trigger https://github.com/FEniCS/dolfinx/actions/workflows/docker-end-user.yml ? After the nightly image is manually rebuilt, I'll trigger a handful of runs in the multiphenicsx repo to see if it is still affected by #2884

I can also trigger my own pipelines, as I've got several tests timing out because of this

[michalhabera]

@jorgensd Can you also remove --config-settings=cmake.define.-DCMAKE_CXX_FLAGS?

[garth-wells]

Let's improve issue and PR names. This is a Docker-only change but the title is very broad.

[jorgensd]

Let's improve issue and PR names. This is a Docker-only change but the title is very broad.

The issue is still a regression issue due to transfering to nanobind. Happy to rename this PR though.

[francesco-ballarin]

Can #2895 be merged before this, and then merge the updated main into this branch? I'll test the combined effect of both.