My IDE is pydev/eclipse on Win XP.
I like the idea of compiling cython modules inside the IDE, but I
can only get it to work on a Linux box.
right-click on the project–>properties–>builders–>new–>program
I have tried with the simplest setup.py and helloworld.pyx as posted here:
http://docs.cython.org/src/userguide/tutorial.html
This is my screen on Linux

It compiles the helloworld.pyx in the usual way, as
python setup.py build_ext –inplace
However, on WinXP, with the same settings, again after clicking
project–>build project
I get

I.e. “is not a valid Win32 application”.
Any clue why this does not work on WinXP?
Update: Problem solved by Fabio. This works:

The error is because it’s trying to execute setup.py as if it was an executable…
The problem in your specific use-case is that external builders know nothing about python, so, the location should actually map to your python.exe (and the setup.py location should be passed as a parameter).