[Qgis-user] Mac OS X: QGIS 1.0 Preview 2 Crashes

[Martin Dobias]

On Fri, Nov 14, 2008 at 7:30 PM, William Kyngesburye
<woklist at kyngchaos.com> wrote:
> On Nov 14, 2008, at 11:07 AM, Martin Dobias wrote:
>
>> Am I right that the problem applies only to bindings (based on
>> SIP/PyQt4), while implementation of embedded python (libqgispython) is
>> okay?
>
>
> Ah, there's a tricky one.  Is libqgispython meant to be a "library", linked
> by other plugins or the Qgis app?  Or is it more like a plugin, loaded by
> Qgis?
>
> I see that none of Qgis, libqgis_* or python/qgis/*.so directly link
> libqgispython.  Yet it is compiled as a library (not bundle) and also links
> directly to the python binary.
>
> If libqgispython is dynamically loaded by Qgis, thet it should also be
> compiled as a bundle and not linked to python.
>
> If libqgispython is meant to be used as a library by other binaries (ie
> python extensions), then it still shouldn't link directly to python, but
> expect Python to be loaded in some way by whatever is linking to it.  It
> would have to compile with -undefined dynamic_lookup then.

libqgispython is meant to be loaded dynamically by QGIS application on
startup. All python-related implementation is in this library, the
rest of application is "python-free", i.e. it doesn't use any
functions directly from python libs.

libqgispython is not meant to be used by anything else than QGIS
application itself.

The main reason of this implementation is that this way we can have
python support (python console and python plugins) optionally, and it
should make life easier for packagers. And second reason, if
libqgispython is not found (or can't be loaded for some reason) when
QGIS starts, nothing fatal happens, just python support is disabled.

I hope this makes things a little clearer...

Martin