Furcsa, most próbáltam egy szűz Debian 10 rendszerre és nekem felment:
# python3 -V
Python 3.7.3
# python3 -m pip install asyncssh
Collecting asyncssh
Downloading https://files.pythonhosted.org/packages/cf/3b/9ac19dc6c722f79b97b7878a4ffc872e36e626071e640532a8947649bbb1/asyncssh-2.1.0-py3-none-any.whl (290kB)
100% |████████████████████████████████| 296kB 1.6MB/s
Collecting cryptography>=2.8 (from asyncssh)
Downloading https://files.pythonhosted.org/packages/45/73/d18a8884de8bffdcda475728008b5b13be7fbef40a2acc81a0d5d524175d/cryptography-2.8-cp34-abi3-manylinux1_x86_64.whl (2.3MB)
100% |████████████████████████████████| 2.3MB 309kB/s
Requirement already satisfied: cffi!=1.11.3,>=1.8 in /usr/local/lib/python3.7/dist-packages (from cryptography>=2.8->asyncssh) (1.13.2)
Requirement already satisfied: six>=1.4.1 in /usr/lib/python3/dist-packages (from cryptography>=2.8->asyncssh) (1.12.0)
Requirement already satisfied: pycparser in /usr/local/lib/python3.7/dist-packages (from cffi!=1.11.3,>=1.8->cryptography>=2.8->asyncssh) (2.19)
Installing collected packages: cryptography, asyncssh
Found existing installation: cryptography 2.6.1
Not uninstalling cryptography at /usr/lib/python3/dist-packages, outside environment /usr
Can't uninstall 'cryptography'. No files were found to uninstall.
Successfully installed asyncssh-2.1.0 cryptography-2.8