低版本PHP无法清理生成的configure文件的问题

今天在用PHP7.1的时候，执行phpize报错：

Cleaning..
Configuring for:
PHP Api Version:         20160303
Zend Module Api No:      20160303
Zend Extension Api No:   320160303
autoconf: warning: both `configure.ac' and `configure.in' are present.
autoconf: warning: proceeding with `configure.ac'.
/usr/bin/m4:configure.ac:6: cannot open `build/ax_gcc_func_attribute.m4': No such file or directory
/usr/bin/m4:configure.ac:8: cannot open `build/php_cxx_compile_stdcxx.m4': No such file or directory
/usr/bin/m4:configure.ac:9: cannot open `build/php.m4': No such file or directory
/usr/bin/m4:configure.ac:10: cannot open `build/pkg.m4': No such file or directory
autom4te: /usr/bin/m4 failed with exit status: 1

执行完phpize --clean之后，依然还是报这个错。发现是phpize --clean无法清理干净之前其他版本PHP生成的configure，所以，得手动删除：

rm configure*

然后重新执行phpize即可。