[Pythonmac-SIG] Problems compiling matplotlib; OR, how to make headers accessible in OS X?

[Kenneth McDonald]

I'm attempting to compile matplotlib, and get messages saying that
it can't find the headers for Tcl/Tk. They exist, they just happen to
be in the Frameworks directories for Tcl and for Tk. I know I can
get this to work by hacking (setting up path variables, putting symbolic
links in directories, or some such), but aside from the fact that that's
a pain and ugly, it doesn't solve the more general problem; if header
files are supposed to be in Frameworks directories (for example, I
found my Tk header files in /Library/Frameworks/Tk.framework/Headers),
what is the best way to set up OS X so that they will be available to 
link
against? Note that I don't know that these headers are supposed to be
there; they just are, and for the time being, I'm assuming that the
person who put together Tk.Framework knew what they were doing.

I also have a more general (and much less important) question relating
to this, purely for my own interest. Why (on all systems, not just on 
OS X)
do we still have to go through this annoyance (and occasionally, 
nightmare)
of requiring access to header sources, in order to link against existing
binaries? Why not simply have the binaries contain all of the 
information
necessary to perform the linking? Is this simply a historical holdover 
from
the fact that it wasn't done that way originally (probably for good 
reasons
at the time), and its too much trouble to change, or are there valid 
reasons
for not doing this still? In some sense, putting headers into a 
Frameworks
structure is an attempt to include that information a part of a package
wrapping the libraries of interest; it seems to me that it would make a
lot more sense (from a design point of view, at least) to include that 
info
in the library binary files themselves.

Thanks,
Ken McDonald