Why am I unable to using rsync to install modules and appear to have to use pip install instead?

[Robert Nicholson]

I’m using Python 3.7.0

so I have multiple environments all on the same architecture with the same python release using anonconda.

What I discovered was that if I install the cryptography module in my dev / uat and then tried to synchronize to production server using rsync I ended up with errors relating to dependencies of the cryptography module. 

Specifically 

Cannot import name ‘_get_backend’

these errors appear to have gone away if I actually use pip install cryptography==3.2.1  instead of using rsync from an existing install machine.

why is this the case?