I tried to do git pull with a rasp pie, but suddenly I got the following error.
I made a new directory and tried to add it remotely, but the same error occurred.
Moreover, the same result was obtained even if the key was recreated and registered in git.

Please comment if you understand anything.

Error message
$git pull origin master
ssh: Could not resolve hostname github.com: Temporary failure in name resolution
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.