cat mkmf.log

have_header: checking for mpg123.h... -------------------- no

"/usr/bin/cc -o conftest -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0/x86_64-darwin12.4.0 -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0/ruby/backward -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0 -I. -I'/opt/boxen/rbenv/versions/2.0.0-p247/include'  -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT   -I/opt/X11/include -O3 -Wno-error=shorten-64-to-32  -pipe conftest.c  -L. -L/opt/boxen/rbenv/versions/2.0.0-p247/lib -L. -L'/opt/boxen/rbenv/versions/2.0.0-p247/lib'  -L/usr/local/lib     -lruby-static  -lpthread -ldl -lobjc "
ld: warning: directory not found for option '-L/usr/local/lib'
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */

"/usr/bin/cc -E -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0/x86_64-darwin12.4.0 -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0/ruby/backward -I/opt/boxen/rbenv/versions/2.0.0-p247/include/ruby-2.0.0 -I. -I'/opt/boxen/rbenv/versions/2.0.0-p247/include'  -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -D_DARWIN_UNLIMITED_SELECT -D_REENTRANT   -I/opt/X11/include -O3 -Wno-error=shorten-64-to-32  -pipe  conftest.c -o conftest.i"
conftest.c:3:10: fatal error: 'mpg123.h' file not found
#include <mpg123.h>
         ^
1 error generated.
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: #include <mpg123.h>
/* end */

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