pyca/cryptography Mac install fails with fatal error: "openssl/opensslv.h" file not found

When install pyca/cryptography on MacOS with python 2.7.18, we got the following error

build/temp.macosx-10.12-x86_64-2.7/_openssl.c:433:10: fatal error: 'openssl/opensslv.h' file not found
#include <openssl/opensslv.h>

Solution

brew install openssl@1.1

pip install cryptography --global-option=build_ext --global-option="-L/usr/local/opt/openssl@1.1/lib" --global-option="-I/usr/local/opt/openssl@1.1/include"

Reference

https://github.com/pyca/cryptography/issues/3489