threadpoolctl fails to detect openblas from the defaults conda channel on Windows

[ogrisel]

Here is a snippet of the CI log of a recent py310_conda windows run.

numpy and openblas are installed from the defaults conda channel:

#
# Name                     Version          Build            Channel
blas                       1.0              openblas
bzip2                      1.0.8            h2bbff1b_6
ca-certificates            2026.7.16        haa95532_0
certifi                    2026.7.22        pypi_0           pypi
charset-normalizer         3.5.1            pypi_0           pypi
colorama                   0.4.6            pypi_0           pypi
coverage                   7.15.4           pypi_0           pypi
cython                     3.2.9            pypi_0           pypi
docutils                   0.23             pypi_0           pypi
exceptiongroup             1.3.1            pypi_0           pypi
flit                       4.0.2            pypi_0           pypi
flit-core                  4.0.2            pypi_0           pypi
idna                       3.19             pypi_0           pypi
iniconfig                  2.3.0            pypi_0           pypi
libexpat                   2.8.2            hd7fb8db_1
libffi                     3.4.8            h42d73b9_3
libopenblas                0.3.31           h9d64744_3
libzlib                    1.3.2            h1c6eee0_0
numpy                      2.2.5            py310hf37ac6a_3
numpy-base                 2.2.5            py310h2ff9e85_3
openssl                    3.5.7            hbb43b14_0
packaging                  26.2             py310haa95532_0
pip                        26.1.2           pyhc872135_0
pluggy                     1.6.0            pypi_0           pypi
pygments                   2.21.0           pypi_0           pypi
pytest                     9.1.1            pypi_0           pypi
pytest-cov                 7.1.0            pypi_0           pypi
python                     3.10.20          hb00fc5c_1
requests                   2.34.2           pypi_0           pypi
scipy                      1.15.3           py310hcca3590_2
setuptools                 83.0.0           py310haa95532_0
sqlite                     3.53.2           hee5a0db_0
threadpoolctl              3.7.0.dev0       pypi_0           pypi
tk                         8.6.15           hf199647_0
tomli                      2.4.1            pypi_0           pypi
tomli-w                    1.2.0            pypi_0           pypi
typing-extensions          4.16.0           pypi_0           pypi
tzdata                     2026c            he532380_0
ucrt                       10.0.22621.0     haa95532_0
urllib3                    2.7.0            pypi_0           pypi
vc                         14.3             h2df5915_12
vc14_runtime               14.44.35208      h4927774_12
vs2015_runtime             14.44.35208      ha6b5a95_12
wheel                      0.47.0           py310haa95532_0
xz                         5.8.2            h53af0af_0
zlib                       1.3.2            h1c6eee0_0

On this run, threadpoolctl detects the openmp runtime but not the blas runtime:

+ python -m threadpoolctl -i numpy scipy.linalg tests._openmp_test_helper.openmp_helpers_inner
[
  {
    "user_api": "openmp",
    "internal_api": "openmp",
    "num_threads": 4,
    "prefix": "vcomp",
    "filepath": "C:\\Windows\\System32\\vcomp140.dll",
    "version": null,
    "thread_limit_scope": "process"
  }
]