using distutils.command.config

I am trying to utilize the config module in distutils to test for
certain headers and libraries and fail elegantly if they are not found
with a helpful message.  The typical gcc error message when a header
is missing is inscrutable to many.

I have subclassed config and can use my class with 


 > python setup.py config

The config class finds all the module specific path and library
information, but I am not clear on the best way to get this to the
build process.  One option is to save the information to a config
file, eg using a plain text format, creating a python module, or using
pickle, but it seems artificial to me to have to use an intermediate
file.  Is there a way to get the config information on a call to 

 > python setup.py build

My config class looks like

from distutils.command.config import config

class config_mpl(config):
    def run (self):
        # make sure you can find the headers, link with the libraries,
        # etc, and collect per module include_dirs, library_dirs,
        # libraries information

One idea is to dump the information from the config call to a
config.pickle, but ideally I would like the config file to be human
readable....

Thanks,
JDH