aspen:python toddysm$ sudo ./setup.py install
Password:
`pkg-config --libs --cflags cld` returns in error:
Package cld was not found in the pkg-config search path.
Perhaps you should add the directory containing `cld.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cld' found

The `cld` C++ library is absent from this system. Please install it.

aspen:~ toddysm$ cd /usr/local/lib/
aspen:lib toddysm$ ls -al
total 2640
drwxr-xr-x  6 root  wheel      204 Jul  2 17:38 .
drwxr-xr-x  9 root  wheel      306 Jul  2 15:17 ..
-rwxr-xr-x  1 root  wheel  1339516 Jul  2 17:38 libcld.0.dylib
lrwxr-xr-x  1 root  wheel       14 Jul  2 17:38 libcld.dylib -> libcld.0.dylib
-rwxr-xr-x  1 root  wheel      918 Jul  2 17:38 libcld.la
drwxr-xr-x  3 root  wheel      102 Jul  2 17:38 pkgconfig
aspen:lib toddysm$ cd pkgconfig/
aspen:pkgconfig toddysm$ ls -al
total 8
drwxr-xr-x  3 root  wheel  102 Jul  2 17:38 .
drwxr-xr-x  6 root  wheel  204 Jul  2 17:38 ..
-rw-r--r--  1 root  wheel  279 Jul  2 17:38 cld.pc

pkg-config --variable pc_path pkg-config

$ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
$ pkg-config --libs --cflags cld