On 9/17/20 3:04 PM, Nicolas Dandrimont wrote:
> 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.

the what-is-python package is now in NEW.  Yes, the policy needs an update.
I'll put that on my TODO list.  If there is too much disagreement about the
python-is-python3 package, then I plan to run it via the CTTE, and ask for an
advice how to move on.


Reply via email to