when="%cxx=msvc %fortran=msvc" seems to be triggering a bug in the concretizer.

Now testing with the fix included from spack/spack#51923.

Edit: seems to work, reverting that...

Rebased this to include the latest Spack version to deal with the concretization issue...

@johnwparent for your information: the last commit removes your constraint that requires cmake@4.1: on windows when cxx,fortran=msvc. The reason for this:

• Previously this constraint was ignored by the concretizer due to a bug, so after removal the status quo is maintained.
• If the constraint is respected, it makes concretization of paraview impossible because it requires both external cmake@3 and cmake@4.1: with paraview %cxx,fortran=msvc

Maybe you could bump external CMake to a newer version in the relevant image and add back the constraint?

IMO the change shouldn't be controversial given that the conflict was ignored from the start and paraview built fine.

There's also always the potential that updating the image might cause other CI failures, so if this is an immediate need, it makes sense to just merge without trying to update the CI image.

I don't love actively introducing a broken relationship between CMake and %fortran=msvc but as Harmen points out, it's a no-op functionally so 🤷‍♂️ .

We also must not actually be using the fortran compiler with CMake in CI, since otherwise I have no idea how that's working... maybe there's a lower bound where oneAPI + MSVC + CMake work again...

The correct solution, as Harmen points out, is to bump the CMake version in the CI image to post 4.1 (and for me to investigate whether there is a lower bound for this conflict) but that may take some time if the image updates introduces other failures.

Thanks for the heads up @haampie

Just commented out the constraint so that we don't forget about it