Dear Alberto, ah, I suspected that. Somehow, the homebrew version of setuptools has a bug that leads it to look in the wrong path. In any case, if you are using homebrew, you might as well use our homebrew formula for kwant to install (installation instructions are given e.g. on the website. Note that in our formula, we are actually using a trick like you do). pip-installed kwant on MacosX will not use Mumps and thus typically be less efficient. Best, Michael On 27-10-15 14:30, Alberto Verga wrote:

Helo, I use python 2.7 and pip from homebrew:

pip 7.1.2 from /usr/local/lib/python2.7/site-packages (python 2.7)

I also verified that installing from the source gives the same error. However, simply putting

export CFLAGS=-I/usr/local/lib/python2.7/site-packages/numpy/core/include/

solves the problem: "python setup.py build" runs smoothly.

Kind regards, Alberto