Describes the cause and action for error messages.
Error Message(English)：
503 service unavailable
Error: 503 Service Unavailable ・ Issue #242 ・ seejohnrun ... - GitHub
https://github.com/seejohnrun/haste-server/issues/242
git pull error "The requested URL returned error: 503 while ...
https://stackoverflow.com/questions/12066100/git-pull-error-the-requested-url-returned-error-503-whi・・・
GitをProxy環境下で使うときにハマった件 - ごずろぐ
http://gozuk16.hatenablog.com/entry/2014/06/06/200602
Git - git clone 失敗の原因解析と対処について｜teratail
https://teratail.com/questions/34645
503 Service Unavailable - MDN - Mozilla
https://developer.mozilla.org/ja/docs/Web/HTTP/Status/503
503エラーを防ぐ！Web屋が知っておくべき503エラーの原因と対処 | 知ら ...
https://www.cpi.ad.jp/column/column01/
神速@503 Service Unavailable on Twitter: "開発に使っているGitHub ...
https://twitter.com/sinsoku_listy/status/1050181350379085824
Working with github.com ? 503: Service Unavailable
https://http503.wordpress.com/2010/08/27/working-with-github-com/
503 error when pushing to git remote - Developer Community
https://developercommunity.visualstudio.com/content/problem/272760/503-error-when-pushing-to-git-rem・・・