Quoting Kurt Siegl (007 at freemail.at):
> 
> Can not compile COW without SDL installed on my machine.
> 
> If not found, it should turn the feature off, like color pixmaps or even RSA.
> 
> checking for sdl-config... no
> checking for SDL - version >= 1.2.4... no
> *** The sdl-config script installed by SDL could not be found
> *** If SDL was installed in PREFIX, make sure PREFIX/bin is in
> *** your path, or set the SDL_CONFIG environment variable to the
> *** full path to sdl-config.
> checking for Mix_OpenAudio in -lSDL_mixer... no
> configure: error: *** Can't find the SDL_mixer library Try: 
> http://www.devolution.com/~slouken/SDL/projects/SDL_mixer/
> make: *** [system.mk] Error 1

What operating systems?

What version of autoconf, automake and aclocal?

% autoconfig --version
% automake --version
% aclocal --version

-- 
Bob Tanner <tanner at real-time.com>         | Phone : (952)943-8700
http://www.mn-linux.org, Minnesota, Linux | Fax   : (952)943-8500
http://www.tcwug.org, Minnesota, Wireless | Coding isn't a crime. 
Key fingerprint = AB15 0BDF BCDE 4369 5B42  1973 7CF1 A709 2CC1 B288