Setting up a Python virtual environment

This topic describes the process to set up a Python virtual environment.

1. Clone the cryptography and maturin repositories:

   $ git clone git@github.com:pyca/cryptography.git
   $ git clone git@github.com:PyO3/maturin.git

2. Set up the C/C++ compilers, along with the appropriate compiler flags:

   $ export CC="ibm-clang_r"
   $ export CXX="ibm-clang++_r"
   $ export CFLAGS="-O3 -fPIC -fno-lto"
   $ export CXXFLAGS="-O3 -fPIC -fno-lto"

3. Set up a virtual environment for the cryptography build with:

   $ python3 –m venv myenv
   $ source myenv/bin/activate && cd cryptography

4. From inside the repo, use pip to install dependencies and the package:

   $ pip3 install setuptools wheel cffi
   $ pip3 install –vvv /path/to/maturin
   $ pip3 install -–no-build-isolation . -vvv