Filing Bugs for Python 3 Switch

[Zbigniew Jędrzejewski-Szmek]

On Thu, Jan 29, 2015 at 05:28:37AM -0500, Bohuslav Kabrda wrote:
> ----- Original Message -----
> > On Wed, Jan 28, 2015 at 11:09:08AM -0500, Bohuslav Kabrda wrote:
> > > Some general notes:
> > > If your package depends on Python because of a Python script that has
> > > /usr/bin/python in hashbang, you need to change this to /usr/bin/python3.
> > > All "Requires" and "BuildRequires" on Python extension modules have to be
> > > changed from "python-foo" to "python3-foo" in order for this change to
> > > work.
> > 
> > Wouldn't it be better to simply say that "Dependencies have to be adjusted
> > so provide the necessary Python 3 modules." ? How to do it depends on the
> > package,
> > sometimes a slightly different set might be used, and simply changing all
> > python-
> > to python3- might not be enough.
> 
> As I noted, this bug is not supposed to be created for "libraries" (i.e. packages that have python- or python3- subpackages), but for "applications" (for example "bind", that has some Python scripts in it, but no Python bindings or importable modules). (Either that answers your question, or I didn't understand the question in which case please try to rephrase it :))

Let's try with an example. Let's say I have some application which
uses python2 and systemd-python. To have it use python3 instead, I have
to change the she-bang, and Requires:systemd-python to Requires:systemd-python3.
Your text does not cover this, because it only talks about packages which
have "python" as a prefix.

As a second example, let's say my hypothetical app uses python-subprocess32,
a backport of Python 3 functionality for Python 2. The dependency would
be updated by simply removing it.

It's hard to provide a general recipe, but packagers usually know what they
are doing, and a general reminder should be enough.

> > > If your package is an "application" (let's call it "foo") and it also
> > > generates a subpackage with Python bindings (i.e. "python-foo" or
> > > "foo-python"), you should provide a python3 subpackage ("python3-foo" or
> > > "foo-python3") and use that as dependency of other subpackages.
> > 
> > This part is unclear. What "other subpackages" and why should the
> > depend on the python3 subpackge?
> 
> To explain it on an example: there's python-dnf and python3-dnf and dnf - all are subpackages generated from a single srpm. Right now, dnf requires python-dnf, but should be switched to require python3-dnf (and all other subpackages generated from dnf.srpm should be switched to require python3-dnf). Does that make it clearer? (I could add this example to the bug description)

This would be helpful.

Zbyszek