[csw-maintainers] Python 2.7

[Maciej (Matchek) Bliziński]

2013/7/18 Peter FELECAN <pfelecan at opencsw.org>:
> "Maciej (Matchek) Bliziński" <maciej at opencsw.org> writes:
>> When that's done, let's discuss what do we want to do about Python
>> 2.7. Peter's concern is that if we keep the versioned directory, it
>> will be hard to transition to 2.7. Peter's objective is to package
>> calibre, which needs Python 2.7 and a number of modules. I suggest
>> that we build Python 2.7 as it was before r21514, in a versioned
>> directory, and we build the necessary modules as CSWpy27-foo.
>
> Naming the new packages CSWpy27-xxx is not a good idea from my
> standpoint. What I propose is when we rebuild a Python module package we
> just use the previous name and have a dependency on CSWpython27.

This will break the 2.6 world. In your scenario:

Before:
CSWpython (which is Python 2.6)
CSWpy-foo (built into the unversioned directory)

#!/opt/csw/bin/python2.6
import foo # works

After:
CSWpython (which is Python 2.6)
CSWpython27
CSWpy-foo (built into the 2.7 versioned directory)

#!/opt/csw/bin/python2.6
import foo # fails

> Also, we should release a new 2.6 package where the /opt/csw/bin/python
> path doesn't exist anymore such as the default Python interpreter will
> be 2.7.

/opt/csw/bin/python should be a symlink driven by alternatives. We
need to think what should be the default if both 2.6 and 2.7 Pythons
are installed. I'm thinking that 2.6 should be the default for now.

>> Maybe we could patch Python 2.7 to look into the unversioned directory
>> for modules – as a backup solution. But we would need to see if this
>> would break anything or not.
>
> It breaks the building of Python 2.7 itself as it will mess with shared
> objects provided by Python 2.6 which are stored in the unversioned
> tree. If there is a way to make Python's byzantine build system to not
> look for shared objects in that path then everything is fine.

So why not simply let Python do its thing, where 2.6 is isolated from
2.7? This is the way it works out of the box. You just build stuff you
need for 2.7 a and you're done.

Maciej