[Qgis-psc] [Fwd: [Qgis-developer] Request of statement about qgis libraries.]

[Paolo Cavallini]

Hi all.
This seems an important and strategic question, should we take a
decision on it?
All the best.
pc

-------- Messaggio Originale  --------
Oggetto: [Qgis-developer] Request of statement about qgis libraries.
Data: Mon, 23 Mar 2009 11:47:10 +0100
Da: Francesco P. Lovergine <frankie at debian.org>
A: qgis-developer at lists.osgeo.org

Hi folks

On the basis of a brief discussion about Qgis 1.0.x libraries this is
the current point of view by Debian packagers about the status of
Qgis SONAMEs.

Currently 1.0.1 uses

Core library:

  SONAME               libqgis_core.so.1.0

Non-core that depends on core:

  SONAME               libqgis_gui.so.1.0
  SONAME               libqgispython.so.1.0

Plugins that depends on core/non-core:

  SONAME               libcoordinatecaptureplugin.so
  SONAME               libcopyrightlabelplugin.so
  SONAME               libdelimitedtextplugin.so
  SONAME               libdelimitedtextprovider.so
  SONAME               libdxf2shpconverterplugin.so
  SONAME               libgeorefplugin.so
  SONAME               libgpsimporterplugin.so
  SONAME               libgpxprovider.so
  SONAME               libgridmakerplugin.so
  SONAME               libinterpolationplugin.so
  SONAME               libmemoryprovider.so
  SONAME               libnortharrowplugin.so
  SONAME               libogrconverterplugin.so
  SONAME               libogrprovider.so
  SONAME               libpostgresprovider.so
  SONAME               libquickprintplugin.so
  SONAME               libscalebarplugin.so
  SONAME               libspitplugin.so
  SONAME               libwfsplugin.so
  SONAME               libwfsprovider.so
  SONAME               libwmsprovider.so

Now, someone said that API for 1.x is frozen, but ABI could change at every
release, i.e. 1.1 would break 1.0 ABI compatibility (is that confirmed?).

That justifies the use of a 1.0 versioning of SONAMEs, but implies that
debian/control uses the wrong name for libqgis*, which should be libqgis1.0
currently instead and libqgis1.1 for Qgis 1.1.x.
It is due to avoid problems with selective upgrades and third-parties
plugins (it is considered a serious bug FYI, because violates Debian
Policy).

If ABI could change for each patchlevel, 1.x.y should be used in SONAMEs,
and package names should change as consequence. So what's definitively
required is fixing a roadmap for API/ABI changes, and following it,
in order to allow distributors doing their work and avoid problems
to other developers and users.

Same considerations apply to Python interface per se, IF both
API and/or ABI changes could be expected independently on the C++ interfaces
(e.g. if python interfaces changed more rapidly).
In that case python related packages should declare their interface level,
to avoid dangerous mixing with compiled objects. At least currently it is
NOT expected on the basis of current package style. But is this true?

Those are currently the major blockers to even _think_ of having Qgis in
Debian again. A well-defined policy need to be stated and followed.

-- 
Francesco P. Lovergine
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-- 
Paolo Cavallini: http://www.faunalia.it/pc