As far as I can tell, PyNaCl is statically linking to libsodium and in doing so is distributing libsodium in its wheels. While the wheels contain libsodium (in binary form) they do not seem to contain the libsodium license, which contains the following text.
- ISC License
- Copyright (c) 2013-2025
- Frank Denis
- Permission to use, copy, modify, and/or distribute this software for any
- purpose with or without fee is hereby granted, provided that the above
- copyright notice and this permission notice appear in all copies.
Libsodium's ISC license should really be present in the PyNaCl wheels.