On Thu, Jun 30, 2016 at 5:20 AM, Jaroslav Reznik <jreznik(a)redhat.com> wrote:
= Proposed System Wide Change: Automatic Provides for Python RPM
Packages =
https://fedoraproject.org/wiki/Changes/
Automatic_Provides_for_Python_RPM_Packages
Change owner(s):
* Tomas Orsava <
https://fedoraproject.org/wiki/User:Torsava>
* Miro Hroncok <
https://fedoraproject.org/wiki/User:Churchyard>
* Email: python-maint(a)redhat.com
Upon building Python packages containing packaging metadata, RPM will
automatically detect the standardized name of the software (i.e. dist name,
name on PyPI) in the canonical format [1] and create a virtual Provides tag
with the value pythonX.Ydist(CANONICAL_NAME), where X.Y is the used Python
version. RPM may also detect dependencies of the software from the metadata
and automatically require them using the same syntax.
== Detailed Description ==
If during the building of a Python package RPM encounters .egg-info, .egg-link
or .dist-info files (provided in Python Wheels and Eggs), it will read the
standardized name of the software (i.e. dist name, name on PyPI) in the
canonical format and create a virtual Provides tag with the value
pythonX.Ydist(CANONICAL_NAME), where X.Y is the used Python version. Note that
the canonical format can differ slightly from the name displayed, for example,
on PyPI.[1]
RPM will also detect dependencies of the software from the aforementioned
metadata files and automatically require them using the format
pythonX.Ydist(). However, because these files don't always contain the full
list of requirements (which are either in setup.py or requirements.txt), the
dependency generator will not be conclusive.
All Python packages will need to be rebuilt so that the virtual Provides tags
are generated and can be used by users, scripts and the requires generator.
== Scope ==
* Proposal owners: Prepare a draft for the Fedora Packaging Guidelines for
Python
* Maintainers of the RPM package: Backport the functionality from upsteram to
Fedora. — Already done thanks to Florian Festi [2]
* Release engineering: Targeted rebuild of Python packages. Ticket [3].
* List of deliverables: All Fedora deliverables will be affected, but only in
a very minor way that in no way jeopardizes their delivery.
* Policies and guidelines: Fedora Packaging Guidelines for Python need to be
updated after the implementation so users know how to take advantage of the
change.
* Trademark approval: Not needed for this Change
[1]
https://fedoraproject.org/wiki/Changes/
Automatic_Provides_for_Python_RPM_Packages#cite_note-canonical-0
It's awesome that this is finally going to make it into Fedora.
However, I strongly advise you have the --majorver-provides enabled
along with the default one, because that way, spec files can be
written in such a way that they can have BuildRequires that aren't
specific to a minor version of Python. The dependency generator
*always* uses the pythonX.Ydist(CANONICAL_NAME) format for generated
dependencies. The addition of pythonXdist(CANONICAL_NAME) Provides
just makes it easier to have BuildRequires for them so that mass
changes for spec files aren't required on every Y version bump.
--
真実はいつも一つ!/ Always, there's only one truth!