[Distutils] PEP 345 and build_requires?

[Sridhar Ratnakumar]

http://goo.gl/zPtX (Google Cache of PEP 345)

PEP 345 introduces `Requires-Dist` metadata field that can be used to define *install-time* requirements. Has anyone thought about having a field that can be used to define *build-time* requirement (similar to setuptools' setup_requires?)? Eg: 

$ grep Build-Requires-Dist lxml-2.2.6/METADATA
Build-Requires-Dist: Cython
Build-Requires-Dist: Scons
$

Or is the only hope to put them all in install_requires/Requires-Dist and have the packagers/installers to resolve and install the dependencies *before* actually attempting to build that module?

-srid