[Distutils] Problems with swig 1.3.6

[Tessa Lau]

Hi all,

I just installed swig 1.3.6 (development version) and it no longer
appears to support the "-dnone" option used by distutils:

swigging src/bnc.i to src/bnc.c
swig -python -dnone -ISWIG -o src/bnc.c src/bnc.i
swig error : Unrecognized option -dnone
Use 'swig -help' for available options.
error: command 'swig' failed with exit status 1

One block of code I added to my setup.py script is to check whether
swig is present on a system.  If it's available, swig the interface
files, otherwise skip the swig step and build the .c files present in
the distribution.  (Unfortunately, everything fails if swig is present
but chokes on the command line you give it.)

Conditional swig invocation would be a great feature to add to distutils.

--Tessa