{"action":"closed","issue":{"url":"https://api.github.com/repos/grpc/grpc/issues/3428","labels_url":"https://api.github.com/repos/grpc/grpc/issues/3428/labels{/name}","comments_url":"https://api.github.com/repos/grpc/grpc/issues/3428/comments","events_url":"https://api.github.com/repos/grpc/grpc/issues/3428/events","html_url":"https://github.com/grpc/grpc/issues/3428","id":107946920,"number":3428,"title":"Jenkins: git checkout fails with \"reference is not a tree\" error.","user":{"login":"jtattermusch","id":9939684,"avatar_url":"https://avatars.githubusercontent.com/u/9939684?v=3","gravatar_id":"","url":"https://api.github.com/users/jtattermusch","html_url":"https://github.com/jtattermusch","followers_url":"https://api.github.com/users/jtattermusch/followers","following_url":"https://api.github.com/users/jtattermusch/following{/other_user}","gists_url":"https://api.github.com/users/jtattermusch/gists{/gist_id}","starred_url":"https://api.github.com/users/jtattermusch/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jtattermusch/subscriptions","organizations_url":"https://api.github.com/users/jtattermusch/orgs","repos_url":"https://api.github.com/users/jtattermusch/repos","events_url":"https://api.github.com/users/jtattermusch/events{/privacy}","received_events_url":"https://api.github.com/users/jtattermusch/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/grpc/grpc/labels/Jenkins","name":"Jenkins","color":"bfd4f2"},{"url":"https://api.github.com/repos/grpc/grpc/labels/P1","name":"P1","color":"ff6666"}],"state":"closed","locked":false,"assignee":{"login":"jtattermusch","id":9939684,"avatar_url":"https://avatars.githubusercontent.com/u/9939684?v=3","gravatar_id":"","url":"https://api.github.com/users/jtattermusch","html_url":"https://github.com/jtattermusch","followers_url":"https://api.github.com/users/jtattermusch/followers","following_url":"https://api.github.com/users/jtattermusch/following{/other_user}","gists_url":"https://api.github.com/users/jtattermusch/gists{/gist_id}","starred_url":"https://api.github.com/users/jtattermusch/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jtattermusch/subscriptions","organizations_url":"https://api.github.com/users/jtattermusch/orgs","repos_url":"https://api.github.com/users/jtattermusch/repos","events_url":"https://api.github.com/users/jtattermusch/events{/privacy}","received_events_url":"https://api.github.com/users/jtattermusch/received_events","type":"User","site_admin":false},"milestone":null,"comments":6,"created_at":"2015-09-23T15:32:56Z","updated_at":"2015-10-16T15:22:24Z","closed_at":"2015-10-16T15:22:24Z","body":"We've been seeing this problem for quite a while now, so I am adding a tracking issue for it.\r\n\r\nSymptoms:\r\nGenerally, this happens when you have an open pull request and force-push the underlying branch (e.g. after you have consolidated/changed the history with `git rebase`). After that, github pull request builder will pick up the change to that branch and start a new build on jenkins. All configurations in that build will fail with the same message \"Could not checkout\" and \"Reference is not a tree\" - everything will be red.\r\n\r\nWorkaround:\r\nHit the Rebuild button on the failed build (if you don't see that button, make sure you're logged in: https://grpc-testing.appspot.com/manage). The new build should be able to checkout everything without problems and you will get your test results.\r\n\r\nCause:\r\nMost likely cause of this problem is this:\r\nhttps://issues.jenkins-ci.org/browse/JENKINS-10385"}}