running either

python runtests.py --bench-compare <commit1> <commit2>

or

spin bench --compare <commit1> <commit2>

will end up calling

cd benchmark; asv continuous --factor 1.05 --bench main <commit1> <commit2>

Then asv creates a virtualenv for each commit, and uses a vanilla pip install to build NumPy. While this can work on macOS and linux (and use the system OpenBLAS), it will fail to correctly use OpenBLAS on windows, since the build also needs to

• copy the OpenBLAS DLL into the correct place
• build the _distributor_init.py file. In CI this is done via additional post-install code:

Is there a way to, if OpenBLAS is found, to do this as part of the build?

Here is what the various CI invocations to do these steps look like:

(on azure this also shows the complicated command line needed)