刚试了一下拉pd的仓库，确实有不稳定的情况，多试几次就好了
heao@LAPTOP-R23HQTUJ MINGW64 /e/heao/git
$ git clone https://github.com/tikv/pd
Cloning into 'pd'...
fatal: unable to access 'https://github.com/tikv/pd/': Failed to connect to github.com port 443 after 21053 ms: Couldn't connect to server
heao@LAPTOP-R23HQTUJ MINGW64 /e/heao/git
$ git clone https://github.com/tikv/pd
Cloning into 'pd'...
fatal: unable to access 'https://github.com/tikv/pd/': Failed to connect to github.com port 443 after 21119 ms: Couldn't connect to server
heao@LAPTOP-R23HQTUJ MINGW64 /e/heao/git
$ git clone https://github.com/tikv/pd
Cloning into 'pd'...
remote: Enumerating objects: 55856, done.
remote: Counting objects: 100% (363/363), done.
remote: Compressing objects: 100% (277/277), done.
remote: Total 55856 (delta 138), reused 195 (delta 69), pack-reused 55493
Receiving objects: 100% (55856/55856), 34.56 MiB | 582.00 KiB/s, done.
Resolving deltas: 100% (39211/39211), done.