First, why use the -dylib_file option, given that its two path arguments are identical? Seems pointless to me. See the following portion of the ld man page:
-dylib_file install_name:file_name
Specifies that a dynamic shared library is in a different
location than its standard location. Use this option when you
link with a library that is dependent on a dynamic library,
and the dynamic library is in a location other than its
default location. install_name specifies the path where the
library normally resides. file_name specifies the path of the
library you want to use instead. For example, if you link to
a library that depends upon the dynamic library libsys and
you have libsys installed in a nondefault location, you would
use this option: -dylib_file /lib/lib-
sys_s.A.dylib:/me/lib/libsys_s.A.dylib.
Second, is the explicit pkg-config call necessary? I routinely remove it (and the -dylib_file option too) and no problems arise. Is this actually needed for folks for use MacPorts? (I don't have /opt/local )
I suppose "better safe than sorry" is a good philosophy to have, but while you are cleaning things up I thought I'd call this matter to your attention. Perhaps other Mac users who build from source can offer their insights.
Thanks,
Louis