Am 14.02.2023 um 15:03 hat Paolo Bonzini geschrieben:
> In the case of Python the issue is not the interpreter per se, though
> there are a couple new feature in Python 3.7 that are quite nice (for
> example improved data classes[1] or context variables[2]). The main
> problem as far as I understood (and have seen in my experience) is
> linting tools. New versions fix bugs that caused false positives, but
> also become more strict at the same time. The newer versions at the
> same time are very quick at dropping support for old versions of
> Python; while older versions sometimes throw deprecation warnings on
> new versions of Python. This makes it very hard to support a single
> version of, say, mypy that works on all versions from RHEL8 and SLE15
> to Fedora 38 and Ubuntu 23.04.
Why do we have to support a single version of mypy? What is wrong with
running an old mypy version with old Python version, and a newer mypy
with newer Python versions?
Sure, they will complain about different things, but it doesn't feel
that different from supporting multiple C compilers in various versions.
It's more like having to support only C++03 on RHEL 8 and only C++20 in Fedora 37, without even being able to use a preprocessor.
For example old versions might not understand some type annotations and will fail mypy altogether, therefore even with newer versions you can't annotate the whole source and have to fall back to non-strict mode.
Paolo