Compiling modules in OSX, eg PyUSB?

[Dr Mephesto]

On Mar 20, 6:23 pm, Philip Semanchuk <phi... at semanchuk.com> wrote:
> On Mar 20, 2009, at 12:36 PM, Dr Mephesto wrote:
>
> > windows? well, I thought that maybe the location of the "usb.h" thing
> > was relevant, and I didnt see it mentioned on the linux instructions.
>
> Oh, OK. Windows is a pretty different animal from Unix/Linux so it's  
> not likely to be of much help here.
>
>
>
> > find /usr -name usb.h -ls   gives me:
> > 3545683       24 -rw-r--r--    1 root     wheel        8360 Mar 20
> > 16:37 /usr/include/usb.h
> > 3538549       24 -rw-rw-r--    1 root     wheel        8360 Feb 22
> > 11:28 /usr/local/include/usb.h
>
> Looks good.
>
> > sudo python setup.py install         this gives me:
> > pcfr147:pyusb-0.4.1 david$ sudo python setup.py install
> > Password:
> > running install
> > running build
> > running build_ext
> > building 'usb' extension
> > gcc -arch ppc -arch i386 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -
> > fno-strict-aliasing -Wno-long-double -no-cpp-precomp -mno-fused-madd -
> > fno-common -dynamic -DNDEBUG -g -O3 -I/Library/Frameworks/
> > Python.framework/Versions/4.1.30101/include/python2.5 -c pyusb.c -o
> > build/temp.macosx-10.3-i386-2.5/pyusb.o
> > In file included from pyusb.c:11:
> > pyusb.h:6:17: error: usb.h: No such file or directory
>
> OK, I think I see what's going wrong, but I don't understand it. I  
> think I was wrong; setup.py doesn't automatically add /usr/include  
> and /usr/local/include to the include path when compiling. I'm basing  
> this on the documentation here, which states that these paths have to  
> be added explicitly:http://docs.python.org/distutils/setupscript.html#preprocessor-options
>
> However, the two C extensions I distribute compile just fine without  
> that, and they certainly rely on /usr/include and /usr/local/include.  
> Strange...
>
> But nevermind that. Looking in the setup.py for PyUSB, I see this  
> special code added for OS X (a.k.a. Darwin):
>
> elif -1 != platform.find("darwin"):
>      extra_link_args = ['-framework',
>                         'CoreFoundation',
>                         '-framework',
>                         'IOKit',
>                         '-L/sw/lib']
>      extra_compile_args = ['-I/sw/include']
>
> The ['-I/sw/include'] tells the compiler what directories to search  
> for include files. The /sw/ tree is specific to Fink, so if you'd used  
> Fink to install libusb then the PyUSB setup would have found it. But  
> you didn't use Fink (nothing wrong with that; I don't either) and so  
> your usb.h landed in /usr/local/include. What you need to do, then, is  
> add that directory to the list.
>
> So change line 32 in the PyUSB setup.py from this:
>      extra_compile_args = ['-I/sw/include']
> to this:
>      extra_compile_args = ['-I/sw/include', '-I/usr/local/include']
>
> The same assumption is made about the linker path. Note the '-L/sw/
> lib'. You'll need to track down your copy of libusb (it's probably in /
> usr/local/lib) and add that to the extra_link_args like so:
>
>      extra_link_args = ['-framework',
>                         'CoreFoundation',
>                         '-framework',
>                         'IOKit',
>                         '-L/sw/lib',
>                         '-L/usr/local/lib']
>
> Run setup again and I bet you'll be off to the races.
>
> You should certainly report this to the package maintainer, and you  
> might also want to point out that the if block starting on line 17 of  
> setup.py and the if block starting on line 26 are both for OS X, but  
> they lead to different results!
>
> Let us know how it works out,
> Philip

Great, that did the job perfectly! Very much appreciated!

I will write to the code maintainer to let them know the fix; I'm sure
their are lots of other people out there that will find your
modification useful.

Thanks again,
Dave