Describes the cause and action for error messages.
Error Message(English)：
failed to connect to github.com port
GithubへPushした際の「Connection refused」エラーについて - Qiita
https://qiita.com/tekityuu449/items/c58c7b9c2a3243a21aaa
proxy環境にてXcodeからGitHubへのpushでエラー - スタック・オーバーフロー
https://ja.stackoverflow.com/questions/45585/proxy%E7%92%B0%E5%A2%83%E3%81%AB%E3%81%A6xcode%E3%81%8B・・・
Could not push--Failed to connect to github.com port 443 ...
https://stackoverflow.com/questions/41196888/could-not-push-failed-to-connect-to-github-com-port-443・・・
unable to access 'https://github.com/GladysProject/gladys ...
https://stackoverflow.com/questions/51237483/unable-to-access-https-github-com-gladysproject-gladys-・・・
Unable to git clone , Failed to connect to github.com port 443 ...
https://stackoverflow.com/questions/33601366/unable-to-git-clone-failed-to-connect-to-github-com-por・・・
Failed to connect to github 443 - Stack Overflow
https://stackoverflow.com/questions/29333319/failed-to-connect-to-github-443
Failed to connect to github.com port 443: Operation timed out ...
https://stackoverflow.com/questions/38663299/failed-to-connect-to-github-com-port-443-operation-time・・・
GitHub - [python] GitHub内にあるスクリプトをインストールできずに困っ ...
https://teratail.com/questions/127129
Improve ease of configuring Git to work with corporate proxy - GitHub
https://github.com/desktop/desktop/issues/2789