Re: [Visualpython-users] building failure from visual-5.2_release.tar.bz2 on Mac OS X10.6.4

[Bruce S. <bas...@nc...>]

Thanks much for the helpful information, Martin. Why don't I have
problems building the native-mode version of VPython on the Mac, using
either Python 2.5 or Python 2.6? The makefile I'm using contains
-bundle_loader.

Bruce Sherwood

On Tue, Jul 20, 2010 at 3:56 AM, Martin Costabel <cos...@wa...> wrote:
> Bruce Sherwood wrote:
>>
>> The missing links all seem to be Python symbols such as
>> _PyExc_RuntimeError and _PyInt_AsLong, which are part of the Python
>> API for connecting to C. I don't have any experience with the darwin
>> environment, but maybe someone on this list will recognize what the
>> problem is.
>
> It is a problem with python-2.6. There the python executable does not export
> the symbols such as PyExc_RuntimeError any more, as it did until python2.5.
>
> Up to python2.5, the external symbols in the python executable were
> identical to those in the python library libpython. The recommended way to
> link python modules on MacOSX (and this is what is coded in src/Makefile.in)
> was to use the "-bundle_loader $PYTHON" flag, meaning that symbols in the
> module were resolved from the python executable. Linking with the python
> library instead led to a runtime error "interpreter version mismatch".
>
> On python2.6 (I haven't looked at later versions yet), this is different.
> Now the python executable itself is linked with the python library. You need
> to link the module with the flag "-undefined dynamic_lookup" instead of
> -bundle_loader. At runtime, the symbols are then looked up from the python
> library.
>
> For the Fink visual-py26 package, I am patching src/Makefile.in
> correspondingly. I have not found a way to link cvisualmodule.so that would
> work both with (Fink's) python2.5 and python2.6.
>
> --
> Martin
>
>