hudson.AbortException: Failed to clone https://isabelle.in.tum.de/repos/isabelle
at hudson.plugins.mercurial.MercurialSCM.clone(MercurialSCM.java:808)
at hudson.plugins.mercurial.MercurialSCM.checkout(MercurialSCM.java:586)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep.checkout(SCMStep.java:125)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:93)
at org.jenkinsci.plugins.workflow.steps.scm.SCMStep$StepExecutionImpl.run(SCMStep.java:80)
at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution.lambda$start$0(SynchronousNonBlockingStepExecution.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)