pip install argon2_cffi
should be all it takes.
But since Argon2 (the C library) isn’t packaged on any major distribution yet,
argon2_cffi vendors its C code which depending on the platform can lead to complications.
The C code is known to compile and work on all common platforms (including x86, ARM, and PPC). On x86, an SSE2-optimized version is used.
If something goes wrong, please try to update your
pip install -U cffi pip setuptools