[Python-Dev] addressing distutils inability to track file dependencies

[Guido van Rossum]

> What do you think is broken with the debug builds?
> I use it routinely and have no problems at all...

I was repeating hearsay.

Here's what used to be broken on Unix: if you built a debug Python but
did not install it (assuming a non-debug Python was already
installed), and then used that debug Python to build a 3rd party
extension, the debug Python's configuration would be ignored, and the
extension would be built with the configuration of the installed
Python instead.  Such extensions can't be linked with the debug
Python, which was the whole point of using the debug Python to build
in the first place.

Jeremy recently fixed this for Unix, and I'm very happy.

But I believe that on Windows you still have to add "--debug" to your
setup.py build command to get the same effect.  I think that using the
debug executable should be sufficient to turn on the debug flags.

More generally, I think that when you use a Python executable that
lives in a build directory, the configuration of that build directory
should be used for all extensions you build.  This is what Jeremy did
in his fix.  (As a side effect, building the Python extensions no
longer needs to be special-cased.)

--Guido van Rossum (home page: http://www.python.org/~guido/)