fatal: unable to access '': Failed to connect to github.com port 443 after 21088 ms: Timed out

这个错误提示是由于连接到github.com的端口443超时导致的。出现这个问题可能是由于网络连接不稳定或者防火墙限制了对该端口的访问。解决这个问题的方法有以下几种：

1. 检查网络连接：确认你的网络连接正常，并且没有被防火墙或其他网络安全设置所限制。

2. 检查代理设置：如果你使用了代理服务器进行网络访问，请确保代理设置正确，并且能够正常连接github.com。

3. 更换网络环境：如果你使用的是企业网络或学校网络，尝试切换到其他网络环境，例如家庭网络或移动数据网络，看看是否能够解决问题。

4. 检查防火墙设置：如果你有防火墙软件或硬件设备，确保对github.com的访问没有被限制。如果有需要，可以尝试禁用防火墙或者添加相应的规则来允许github.com的访问。

相关问题

fatal: unable to access 'https://github.com/.git/': Failed to connect to github.com port 443 after 21059 ms: Timed out

该报错通常是由于无法连接到github.com导致的。可能的原因有两个：
1. DNS解析出现问题。可以在cmd窗口中输入"ipconfig/flushdns"，清除缓存后重新进行git操作。
2. 防火墙或代理设置。可以取消代理设置，输入以下命令：
git config --global --unset http.proxy
git config --global --unset https.proxy

回答完问题后的

fatal: unable to access 'https://github.com/rogersce/cnpy.git/': Failed to connect to github.com port 443 after 21096 ms: Timed out

This error message indicates that the Git client was unable to connect to the GitHub server at the specified URL. The error "Failed to connect to github.com port 443" suggests that the connection was blocked or refused by the server, possibly due to a network issue or a firewall blocking the connection. The "Timed out after 21096 ms" message implies that the connection attempt took too long and the server timed out waiting for a response.

To fix this issue, you can try the following:

1. Check your internet connection: Ensure that your internet connection is stable and working properly.

2. Check your firewall settings: If you have a firewall enabled, make sure that it is not blocking the connection to GitHub. You may need to add an exception for Git in your firewall settings.

3. Try a different network: If the issue persists, try connecting from a different network, such as a different Wi-Fi network or a cellular data network.

4. Check if GitHub is down: Sometimes, GitHub may experience downtime or maintenance, causing connection issues. You can check the GitHub status page to see if there are any reported issues.

5. Use SSH instead of HTTPS: If you continue to have trouble connecting via HTTPS, you can try using SSH instead. You'll need to generate an SSH key and add it to your GitHub account. Then, you can use the SSH URL instead of the HTTPS URL to clone the repository.