Packaging Python modules for Python 3
I hope to add a parallel-installable Python 3 stack to Fedora 13.
See the feature page: https://fedoraproject.org/wiki/Features/Python3F13 and also this thread: https://www.redhat.com/archives/fedora-devel-list/2009-October/msg00054.html
This requires us to come up with a sane way to package Python 3 modules, and this requires us to generalize our python packaging rules to support more than one python runtime.
The existing Python packaging guidelines are here: Packaging/Python
Runtimes
There will be multiple python runtimes, one for each supported major/minor release combination.
Each runtime corresponds to a binary of the form /usr/bin/python$MAJOR.$MINOR
One of these python runtimes is the "system runtime". It can be identified by the destination of the symlink /usr/bin/python
Naming
(to be written)
Layout
Proposed rule: All files with an extension of .py/.pyo/.pyc MUST be either
- within a runtime package, and below
/usr/lib/python$MAJOR-$MINORfor that runtime, or - for a specific runtime package, and below
/usr/lib/python$MAJOR-$MINOR/site-packagesfor that runtime, or - for the system python runtime.
For example, python code for the 3.1 runtime needs to be below /usr/lib/python3.1/site-packages
.pyo/.pyc files
Compiled .pyo/.pyc files embed a magic number, indicating which python version they are for; python libraries have a corresponding magic number.
Proposed rule: All .pyo/.pyc files below /usr/lib/python$MAJOR.$MINOR MUST have a magic number corresponding to that for /usr/bin/python$MAJOR.$MINOR
Thus e.g. /usr/lib/python2.6/site-packages/libxml2.pyc must have the same magic number as that of /usr/bin/python2.6
Similarly, /usr/lib/python3.1/site-packages/libxml2.pyc must have the same magic number as that of /usr/bin/python3.1
TODO: write an rpmlint test for this. See initial work here: https://www.zarb.org/pipermail/rpmlint-discuss/2009-October/000775.html and here: http://dmalcolm.fedorapeople.org/rpmlint/add-tests-for-python-bytecode-files.patch