On MAC Os BigSur (11.1)
I've being facing issues all day with numpy failing install (with pandas) for Python 3.9.1.6 and poetry 1.1.4.
I understood that poetry uses pip which does not use the wheel version of numpy when pip <= 20.2.x. And fresh installation of Python 3.9.1.6 does not upgrade pip !
This is how I managed to install what I needed :
First check the default version of Python linked to poetry (reinstall it if it does not fit)