Eh?
$ apt-cache policy python3
python3:
Installed: 3.9.1-1
Candidate: 3.9.1-1
Version table:
*** 3.9.1-1 900
900 http://ftp.us.debian.org/debian testing/main amd64 Packages
100 /var/lib/dpkg/status
3.7.3-1 800
800 http://ftp.us.debian.org/debian stable/main amd64 Packages
This is tracking stable+testing, so usually running the version from
testing.
testing has 3.9 and stable has 3.7.
What if I need 3.9 but do not want to touch testing on my production server?
Or how can I migrate to 3.10 (which will be released soon) if even bullseye will have only 3.9?
Docker is the answer)
Unless you need *exactly* 3.9.0, and 3.9.1 won't do - in which case I
question your use case; anything with that tight of a version dependency
on its runtime seems risky to me at best.
I agree that code shouldn't depend on the minor version, but some people think that
developer machines, staging and production should have the same version to make bugs 100% reproducible, and this is one more reason to use Docker.