Jenkins Git Plugin, SCM Polling, and Duplicate Builds
I have a Jenkins instance running inside a firewall performing builds against a GitHub hosted repository. Because of the firewall and security concerns, GitHub webhooks are not an option for triggering builds, but I still have a requirement to build every commit. Enter the SCM polling feature of the Jenkins Git plugin . With this feature enabled, a Jenkins job will poll the repository based on a schedule you define (using a cron-style schedule) and trigger a build for each change it sees based on the refspec you defined for your repository. This is great, except that in my case, Jenkins was kicking off a build of the repository head on every poll, despite there being no new commits. After a bunch of head scratching and exercising my google-foo, I finally stumbled upon a thread on the Jenkins mailing list that described an issue very similar to mine. One of the recommendations was to set the "Force polling using workspace" under "Additional Behaviours" in