setup.py adds in various places hardcoded paths to locations in the filesystem that may contain libraries/includes to compile a given module or feature.

While this behaviour is probably interesting for some users, it is undesirable for distributions that use a package manager to track and install dependencies in a given offset on top of a host system such as Mac OS X, Solaris, AIX, HPUX, etc.

Examples are:
http://trac.macports.org/browser/trunk/dports/lang/python26/files/patch-setup.py.diff
http://www.mail-archive.com/openpkg-dev@openpkg.org/msg09547.html
http://overlays.gentoo.org/proj/alt/browser/trunk/prefix-overlay/dev-lang/python/files/python-2.5.1-no-usrlocal.patch

It would be great if there was a way to disable setup.py from looking for hardcoded paths, and instead completely rely on the behaviour of compiler and linker (or e.g. CFLAGS as given)