The failure is in the Check OpenBLAS version step, which fails to import numpy on windows:

DLL load failed while importing _multiarray_umath: The specified module could not be found

That CI step is no longer relevant since the build uses "whatever version is supplied by pip install scipy-openblas" and not a version fixed by a CI environment variable. But I would expect it to fail on the version check, and not when importing NumPy.

Something is strange in the CI windows run. It has a "Download/Install OpenBLAS" step, which is not needed when using the scip-openblas wheels. During the build, the meson discovery is finding scipy-openblas found: YES 0.3.24.dev, so it is using the wheel to build. But then it is copying the OpenBLAS from the non-scipy-openblas wheel. I think the 'Download / Install OpenBLAS', Copy OpenBLAS DLL to site-packages, and the 'Check OpenBLAS version' build steps should be removed, like on main.

@charris CI is passing