Re: The python command in Debian
Hi Matthias, others,
On Thu, Jul 9, 2020, at 15:26, Matthias Klose wrote:
> As written in [1], bullseye will not see unversioned python packages and the
> unversioned python command being built from the python-defaults package.
>
> It seems to be a little bit more controversial what should happen to the python
> command in the long term. Some people argue that python should never point to
> python3, because it's incompatible, however Debian will have difficulties to
> explain that decision to users who start with Python3 and are not aware of the 2
> to 3 transition. So yes, in the long term, Debian should have a python command
> again.
>
> One solution could be not to ship the python command in bullseye, forcing users
> to adjust their local installations. This has the advantage that the error of
> an unknown interpreter should be pretty clear. But leaves users without a
> python command for the next two years until bullseye+1.
>
> Describing here a solution which is implemented for Ubuntu focal (20.04 LTS). A
> new source package what-is-python (-perl-dont-hurt-me) ships binary packages
> python-is-python2, python-dev-is-python2, python-is-python3 and
> python-dev-is-python3. The python-is-python2 package provides the python
> package, such that packages that still depend on python are not removed on a
> distro upgrade. On new installs, python-is-python3 is not installed by default,
> but the user gets a hint from command-not-found to install the package if he
> tries to run python. Package dependencies on the new four binary packages have
> to be disallowed in the Python policy. Note that such a package including the
> Provides should only be uploaded once all dependencies on the unversioned python
> packages are gone.
So I see that the removal of `/usr/bin/python`-shipped-by-python-defaults has happened as planned. Thanks!
I've just got a friend ask me about what to do to get /usr/bin/python to point at python3; Do you have any plan of uploading what-is-python for use in bullseye, at least without the python-is-python2 Provides for python as a first step (to keep the current "breakage")?
In any case I think the python packaging policy at https://www.debian.org/doc/packaging-manuals/python-policy/ch-python.html should get an update to match the current status quo related to /usr/bin/python; My friend looked at it and were confused not to find a /usr/bin/python anymore.
Thanks,
--
Nicolas Dandrimont
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