def remove_existing_links(root_dir):
    """Delete any symlinks present at the root of a directory.

    Parameters
    ----------
    root_dir : `str`
        Directory that might contain symlinks.

    Notes
    -----
    This function is used to remove any symlinks created by `link_directories`.
    Running ``remove_existing_links`` at the beginning of a build ensures that
    builds are isolated. For example, if a package is un-setup it won't
    re-appear in the documentation because its symlink still exists.
    """
    logger = logging.getLogger(__name__)

    for name in os.listdir(root_dir):
        full_name = os.path.join(root_dir, name)
        if os.path.islink(full_name):
            logger.debug('Deleting existing symlink {0}'.format(full_name))
            os.remove(full_name)