matplotlib setup is trying to build macosx extension on linux ?

Hi,

    I updated matplotlib to 0.99.1, and got a weird build failure:

gcc: error trying to exec 'cc1obj': execvp: No such file or directory

I realized that cc1obj stands for the objective C compiler, and that it
is trying to build the macosx extension, but I am on Ubuntu with python
2.6, so it does not make much sense. The following lines in setup.py are
a bit suspicious:

if options['build_macosx']:
    if check_for_macosx() or (options['build_macosx'] is True):
        build_macosx(ext_modules, packages)
        rc['backend'] = 'MacOSX'

This would always build the mac os x extension if
options['build_macosx'] is True, which is the case for me (it is set-up
in setup.cfg, which I did not touch).

I am a bit surprised to see this, as I am sure I am far from being the
first one to build this version of matplotlib on Ubuntu,

cheers,

David