Push event to branch 18.09
Connecting to https://api.github.com using docker-jenkins/****** (docker-jenkins GitHub credentials)
java.net.SocketException: Socket closed
	at java.net.SocketInputStream.read(SocketInputStream.java:204)
	at java.net.SocketInputStream.read(SocketInputStream.java:141)
	at sun.security.ssl.InputRecord.readFully(InputRecord.java:465)
	at sun.security.ssl.InputRecord.read(InputRecord.java:503)
	at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:975)
	at sun.security.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:933)
	at sun.security.ssl.AppInputStream.read(AppInputStream.java:105)
	at okio.Okio$2.read(Okio.java:139)
	at okio.AsyncTimeout$2.read(AsyncTimeout.java:211)
Caused: java.net.SocketTimeoutException: timeout
	at okio.Okio$3.newTimeoutException(Okio.java:207)
	at okio.AsyncTimeout.exit(AsyncTimeout.java:261)
	at okio.AsyncTimeout$2.read(AsyncTimeout.java:215)
	at okio.RealBufferedSource.indexOf(RealBufferedSource.java:306)
	at okio.RealBufferedSource.indexOf(RealBufferedSource.java:300)
	at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:196)
	at com.squareup.okhttp.internal.http.Http1xStream.readResponse(Http1xStream.java:186)
	at com.squareup.okhttp.internal.http.Http1xStream.readResponseHeaders(Http1xStream.java:127)
	at com.squareup.okhttp.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:737)
	at com.squareup.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:609)
	at com.squareup.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:460)
	at com.squareup.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:399)
	at com.squareup.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:527)
	at com.squareup.okhttp.internal.huc.DelegatingHttpsURLConnection.getResponseCode(DelegatingHttpsURLConnection.java:105)
	at com.squareup.okhttp.internal.huc.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:25)
	at org.kohsuke.github.Requester.parse(Requester.java:615)
Caused: org.kohsuke.github.HttpException: Server returned HTTP response code: -1, message: 'null' for URL: https://api.github.com/repos/docker/cli/git/refs/heads/18.09
	at org.kohsuke.github.Requester.parse(Requester.java:646)
	at org.kohsuke.github.Requester.parse(Requester.java:644)
	at org.kohsuke.github.Requester.parse(Requester.java:644)
	at org.kohsuke.github.Requester.parse(Requester.java:607)
	at org.kohsuke.github.Requester._to(Requester.java:285)
	at org.kohsuke.github.Requester.to(Requester.java:247)
	at org.kohsuke.github.GHRepository.getRef(GHRepository.java:891)
	at org.jenkinsci.plugins.github_branch_source.GitHubSCMSource.retrieve(GitHubSCMSource.java:1602)
	at jenkins.scm.api.SCMSource.fetch(SCMSource.java:582)
	at org.jenkinsci.plugins.workflow.multibranch.SCMBinder.create(SCMBinder.java:98)
	at org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:293)
	at hudson.model.ResourceController.execute(ResourceController.java:97)
	at hudson.model.Executor.run(Executor.java:429)
Finished: FAILURE