• [ x] I am on the latest Poetry version.
• [ x] I have searched the issues of this repo and believe that this is not a duplicate.
• [ x] If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Big Sur 11.0.1
• Poetry version: 1.1.4
• x86

Issue

When I try to install packages poetry trys to install from source, which can lead to various build failuers. But if I use pip 20.3 or greater I can download the wheel.

 pip install numpy==1.18.5
Looking in indexes: https://pypi.org/simple
Collecting numpy==1.18.5
  Downloading numpy-1.18.5-cp37-cp37m-macosx_10_9_x86_64.whl (15.1 MB)
     |████████████████████████████████| 15.1 MB 5.8 MB/s
Installing collected packages: numpy
Successfully installed numpy-1.18.5

will work fine for example. My guess is the version of pip poetry install uses is too old.