When submitting jobs to Jenkins via SSH (ssh build@jenkins build -v -f job) an intermittent "ERROR: Null" occurs when the job is started on Jenkins.

This error terminates the SSH connection to Jenkins, so no build output nor build status is available - the job is "lost", although it will be executed by Jenkins.

The attached zip file has a minimal Jenkins job, a shell procedure that will trigger the bug and some sample output, as well as the list of plugins active on the jenkins installation.

The Jenkins installation has a mix of ubuntu, sles, osx and windows(cygwin) slaves - 71 machines providing 156 executors all connected via SSH. When run without restriction to a subset of executors the script runs for almost 12 minutes (5 batches with 5 jobs, each with a max duration of 13 seconds!) and the error rate is very high. When run with a restriction that singles out 8 slaves, the same job requires a bit more than 2 minutes and the error rate is much lower.