Describes the cause and action for error messages.
Error Message(English)：
jenkins cannot access github
"Failed to connect to repository" Error while setting up Github ...
https://stackoverflow.com/questions/12681308/failed-to-connect-to-repository-error-while-setting-up-・・・
Jenkins is unable to download the github repository
https://stackoverflow.com/questions/33961010/jenkins-is-unable-to-download-the-github-repository
Authenticate Jenkins CI for Github private repository
https://stackoverflow.com/questions/5212304/authenticate-jenkins-ci-for-github-private-repository
jenkins/hudson can't connect to github repo
https://stackoverflow.com/questions/10224574/jenkins-hudson-cant-connect-to-github-repo
GitHub Plugin - Jenkins - Jenkins Wiki
https://wiki.jenkins.io/display/JENKINS/GitHub+Plugin
Manual Mode
https://wiki.jenkins.io/display/JENKINS/GitHub+Plugin#GitHubPlugin-ManualMode
Automatic Mode (Jenkins ...
https://wiki.jenkins.io/display/JENKINS/GitHub+Plugin#GitHubPlugin-AutomaticMode(Jenkinsmanageshooks・・・
Using cache to GitHub ...
https://wiki.jenkins.io/display/JENKINS/GitHub+Plugin#GitHubPlugin-UsingcachetoGitHubrequests
Windows
https://wiki.jenkins.io/display/JENKINS/GitHub+Plugin#GitHubPlugin-Windows: