[DebianGIS-dev] Bug#483400: python-mapscript: Cannot import mapscript module into python.

[Francesco P. Lovergine]

forwarded 483400 mapserver-users at lists.umn.edu
tags 483400 + confirmed
tags 483400 + upstream
tags 483400 + pending
thanks

On Wed, May 28, 2008 at 11:13:21AM -0600, Hays Barrett wrote:
> Package: python-mapscript
> Version: 5.0.2-2+b1
> Severity: grave
> Justification: renders package unusable
> 
> With the transision to AGG in mapserver\mapscript 5.0, the mapscript modlule fails to import in python.
> 
> Example:
> 
> Python 2.5.2 (r252:60911, Apr 17 2008, 13:15:05)
> [GCC 4.2.3 (Debian 4.2.3-3)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import mapscript
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/usr/lib/python2.5/site-packages/mapscript.py", line 7, in <module>
>     import _mapscript
> ImportError: /usr/lib/python2.5/site-packages/_mapscript.so: undefined symbol: _ZN3agg12g_sqrt_tableE
> >>>
> 
> 

First of all, mapserver on Debian uses an embedded (and static) version
of AGG 2.4 libraries, not the system -dev package for 2.5, due to known 
licensing issues. 

Note that currently shared libs for AGG are deprecated due to
intensive use of templates (upstream justification, not mine), 
so that in 2.5 there are no more shlibs available, too.

Unfortunately, the setup.py script roughly processes mapserver
mapscriptvars and due to the -shared flag use leaves out the external
symbols of the two AGG libs used, because it supposes they are available
as shlib. I'll add a tiny patch to link in the two .a libraries by
manipulating the mapscriptvars, but a different strategy should be
provided at upstream level to manage this case.

Of course with the old 2.4 (which had shlibs available) that was not
an issue. 

Cheers and thanks.

-- 
Francesco P. Lovergine