Nothing new to the latest bug report, just to confirm in a clean system:
$ docker images debian:sid REPOSITORY TAG IMAGE ID CREATED SIZE debian sid 484ec39d2458 13 days ago 125MB $ docker run -it debian:sid /bin/bash root@58046e5023c2:/# apt update && apt upgrade -y && apt install -y python3-aiohttp root@58046e5023c2:/# python3 -c "import aiohttp" Traceback (most recent call last): File "/usr/lib/python3/dist-packages/aiohttp/client_reqrep.py", line 70, in <module> import cchardet as chardet ModuleNotFoundError: No module named 'cchardet' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "<string>", line 1, in <module> File "/usr/lib/python3/dist-packages/aiohttp/__init__.py", line 6, in <module> from .client import ( File "/usr/lib/python3/dist-packages/aiohttp/client.py", line 59, in <module> from .client_reqrep import ( File "/usr/lib/python3/dist-packages/aiohttp/client_reqrep.py", line 72, in <module> import charset_normalizer as chardet # type: ignore[no-redef] ModuleNotFoundError: No module named 'charset_normalizer' root@58046e5023c2:/# root@58046e5023c2:/# dpkg -l | grep -i python3-aiohttp ii python3-aiohttp 3.8.1-2 amd64 http client/server for asyncio And like Jörg: root@58046e5023c2:/# apt install -y python3-charset-normalizer root@58046e5023c2:/# python3 -c "import aiohttp" root@58046e5023c2:/# Cheers, -- Carles Pina i Estany https://carles.pina.cat