最近在OS X EI Capitan系统上执行升级工作的时候，发生错误，内容如下：
$ brew upgrade cmake ==> Upgrading 1 outdated package: cmake 3.17.3 -> 3.20.3 ==> Upgrading cmake 3.17.3 -> 3.20.3 ==> Downloading https://www.bytereef.org/contrib/decimal.diff Already downloaded: /Users/longsky/Library/Caches/Homebrew/downloads/f60b5004541eb3c87cce87ef3bf94933a2684ab267346afdc45ae1622ffa923a--decimal.diff ==> Downloading https://files.pythonhosted.org/packages/f6/e9/19af16328705915233299f6f1f02db95899fb00c75ac9da4757aa1e5d1de/setuptools-56.0.0.t curl: (22) The requested URL returned error: 403 [[[!!! BREAKING CHANGE !!!]]] Support for clients that do not support Server Name Indication is temporarily disabled and will be permanently deprecated soon. See https://status.python.org/incidents/hzmjhqsdjqgb and ht Error: Failed to download resource "python@3.9--setuptools" Download failed: https://files.pythonhosted.org/packages/f6/e9/19af16328705915233299f6f1f02db95899fb00c75ac9da4757aa1e5d1de/setuptools-56.0.0.tar.gz
排查了很久，发现是以前为了修复 解决macOS系统curl报告https证书不正确(curl: (60) SSL certificate problem: Invalid certificate chain)问题而配置了curl忽略安全配置信息导致的，如下：
$ cat .curlrc --insecure
移除这个配置项目即可解决问题。