Re: [Discuss-gnuradio] Cygwin install problem

[Don Ward]

Rob Walker wrote:

> I have a working version of GNU Radio 3.0.3 on a Cygwin system and just 
> tried to install 3.1.2.   I followed the instructions on the wiki page and 
> configure went ok but I got the following error message during the make:
>
> In file included from /usr/include/python2.5/Python.h:57,
>                 from video_sdl.cc:129:
> /usr/include/python2.5/pyport.h:230:24: sys/select.h: No such file or 
> directory

When building under Cygwin, the SDL package specifies flags to build native 
Windows code (using MinGW include files) without the Cygwin compatibility 
library.  This should work except that the flags used (-mno-cygwin, in 
particular) are stored in sdl.pc (the pkg-config configuration file) and 
picked up by GNU Radio.  When these flags are used to build the Python 
extension module, they prevent Cygwin-specific include files (e.g., 
<sys/select.h>) used by Python.h from being found.

In essence, ./configure is determining what libraries are available on one 
system (Cygwin) while the flags read by pkg-config for SDL are specifying 
flags for a different system (native Windows, using MinGW include files). 
(Note that the actual conflict here comes from pyconfig.h, which should 
agree with ./configure as to what include files are available.)

A possible workaround for this case is to override the SDL flags in the 
pkg-config file:

cd gnuradio-3.1.2
export SDL_CFLAGS =I/usr/local/include/SDL
export SDL_LIBS=-lSDL
./configure ...

This compiles and links without errors, but I haven't been able to test 
whether gr-video-sdl works or if SDL's opting to bypass the Cygwin library 
causes problems for this application.

Is there a better solution?  Should SDL be putting flags like -mno-cygwin in 
sdl.pc?

-- Don W.