### 3.3.4 Library options

You can also specify the libraries to link against when building your extension, and the directories to search for those libraries. The `libraries` option is a list of libraries to link against, `library_dirs` is a list of directories to search for libraries at link-time, and `runtime_library_dirs` is a list of directories to search for shared (dynamically loaded) libraries at run-time.

For example, if you need to link against libraries known to be in the standard library search path on target systems

      Extension(...,
                libraries=["gdbm", "readline"])

If you need to link with libraries in a non-standard location, you'll have to include the location in `library_dirs`:

      Extension(...,
                library_dirs=["/usr/X11R6/lib"],
                libraries=["X11", "Xt"])

(Again, this sort of non-portable construct should be avoided if you intend to distribute your code.)

** still undocumented: extra_objects, extra_compile_args, extra_link_args, export_symbols--none of which are frequently needed, some of which might be completely unnecessary! **