import numpy
import chainer

/Users/xxx/Library/Python/3.8/lib/python/site-packages/chainer/_environment_check.py:33: UserWarning: Accelerate has been detected as a NumPy backend library.
vecLib, which is a part of Accelerate, is known not to work correctly with Chainer.
We recommend using other BLAS libraries such as OpenBLAS.
For details of the issue, please see
Tips and FAQs — Chainer 7.8.1 documentation
docs.chainer.org

Please be aware that Mac OS X is not an officially supported OS.

  warnings.warn('''\

$ brew install openblas

$ pip uninstall numpy

[openblas]
libraries = openblas
library_dirs = /usr/local/opt/openblas/lib
include_dirs = /usr/local/opt/openblas/include

pip install --no-binary :all: numpy

$ python -c "import numpy; print(numpy.show_config())"

blas_mkl_info:
  NOT AVAILABLE
blis_info:
  NOT AVAILABLE
openblas_info:
  libraries = ['openblas', 'openblas']
  library_dirs = ['/usr/local/opt/openblas/lib']
  language = c
  define_macros = [('HAVE_CBLAS', None)]
  runtime_library_dirs = ['/usr/local/opt/openblas/lib']
 ...

blas_mkl_info:
  NOT AVAILABLE
blis_info:
  NOT AVAILABLE
openblas_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/opt/openblas/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
blas_opt_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/opt/openblas/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
lapack_mkl_info:
  NOT AVAILABLE
openblas_lapack_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/opt/openblas/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]
lapack_opt_info:
    libraries = ['openblas', 'openblas']
    library_dirs = ['/usr/local/opt/openblas/lib']
    language = c
    define_macros = [('HAVE_CBLAS', None)]