Although these sources are configured for darwin-8.0.1-x86, 
I was able to build them on debian by editing the libtool    
file.  Configuring on debian did not work for me, because 
of a bogus sdl dependence, probably due to pkg-config version
related breakage.  This might be due to some peculiarity of
my setup.  I had the same problem with higher versions
of the software on debian.  I haven't yet tried the higher 
versions on darwin-x86.   

This qrencode binary might run unmodified on some darwin-x86
systems, although some libpng tweaking might be required.

If you try to build, you might have to edit the Makefile.

$(OBJEXT) -> o

I might add more notes here as the situation evolves.

Regards,
proclus
http://www.gnu-darwin.org/