Hey there, I’ve run into this exact issue before — let’s walk through the most effective fixes to get your clones working again:

• Verify your basic network connectivity
  First, check if you can actually reach GitHub. Open your browser and try loading the GitHub website — if that times out too, the problem is with your network (ISP restrictions, firewall, or proxy issues). You can also run ping github.com in your terminal; if you don’t get responses, that confirms a network block.

• Switch to SSH instead of HTTP
  Port 80 for HTTP is often blocked by firewalls or corporate networks. Using SSH bypasses this. Try cloning with the SSH URL instead:

  git clone git@github.com:symfony/symfony.git
  

  Note: You’ll need to have an SSH key added to your GitHub account first (you can find steps to generate and add one directly in your GitHub account settings).

• Configure Git to use a proxy (if applicable)
  If you’re behind a corporate or residential proxy, Git might not be using it by default. Set the proxy settings globally:

  git config --global http.proxy http://your-proxy-address:port
  git config --global https.proxy http://your-proxy-address:port
  

  If you don’t need a proxy anymore, clear these settings with:

  git config --global --unset http.proxy
  git config --global --unset https.proxy
  

• Check local firewall/antivirus software
  Your local firewall or antivirus might be blocking Git’s outgoing requests. Temporarily disable it (just for testing) and try cloning again. If it works, add Git to the allowed apps list in your security software.

• Use a GitHub mirror (for restricted regions)
  If you’re in a region where GitHub access is slow or restricted, try a mirrored repository. For example:

  git clone https://github.com.cnpmjs.org/symfony/symfony.git
  

  Keep in mind mirrors might not be 100% up-to-date, but they’re a reliable workaround for connectivity issues.

• Increase Git’s timeout threshold
  Sometimes the issue is just slow network speed. Extend Git’s timeout settings to give it more time to connect:

  git config --global http.timeout 300
  

  This sets the timeout to 300 seconds (5 minutes) — adjust the number if needed.

Start with the first step (network check) since that’s the root of most timeout issues, then work through the others until you find what works for you!

内容的提问来源于stack exchange，提问作者Elodie G.