[Distutils] How to add include dirs for compiler

[Dragons Spam Account]

How do I inform distutils of addition include directories to find headers in
when compiling c source in a python module.

This is outside the package. I'm a user not the author.


My scenerio:

I installed one module that provides a header file.

Rather than inflict my additions on all the users of the system
I'm installing locally to my own home directory with --home=~

This pops the libraries and such into ~/lib/python but drops the header
file into ~/include python. 

For the sake of python finding ~/lib/python, PYTHONPATH suffices.

Now I attempt to install a second seperate module that relies
on the first module. Regardless of whether I install this second
module to the system or just to my home directory it needs to
find that header and I can't seem to find the interface through
which to provide distutils with additional include directories
to use when compiling source. Which in this case would be ~/include/python.

The whole scenerio works fine if I'm installing everything to 
the system python directories but currently this is not an option
for these modules.

Any help?