[CM] compiling on OS X?

[Bill Schottstaedt]

How did you get gtk?  I haven't had any luck with it in OSX
for a long time.  The Snd configure script uses pkg-config
to find ruby and gtk, so 

pkg-config gtk+-3.0 --cflags

and something similar with ruby should give some info
as to what went wrong.  There's an environment variable
PKG_CONFIG_PATH that sets where pkg-config looks.
Also, there's a longstanding problem with Ruby (that
I reported a long time ago but got no response), so if
ruby.pc is missing, Mike Scholz provided a script to
create it:

make-config-pc.rb > ruby.pc