'Install under the prefix directory'

def install(self, spec, prefix):

    for f in ['README.md', 'Issues.txt']:
        if os.path.isfile(f):
            install(f, join_path(self.prefix, f))
    dirs = ['doc', 'etc', 'tutorials']
    if ('+source' in spec):
        dirs.append('src')
    for d in dirs:
        install_tree(d, join_path(self.prefix, d))
    for d in ['lib']:
        install_tree(join_path(self.build_userdir, d), join_path(self.prefix, d))
