Testing Jenkins 2.138.2 LTS, Jenkins pipelines that use sh intermittently throw the following message in the console log …

sh: line 1:  4449 Terminated              sleep 3

 … and sometimes this … 

sh: line 1: 13136 Terminated              { while [ ( -d /proc/$pid -o ! -d /proc/$$ ) -a -d '/home/ec2-user/workspace/admin-smoke-test@tmp/durable-523481b0' -a ! -f '/home/ec2-user/workspace/admin-smoke-test@tmp/durable-523481b0/jenkins-result.txt' ]; do    touch '/home/ec2-user/workspace/admin-smoke-test@tmp/durable-523481b0/jenkins-log.txt'; sleep 3;{{done; }}}

Jenkins master runs from a Docker image based on jenkins/jenkins:2.138.2-alpine with specific plugins baked into the image by /usr/local/bin/install-plugins.sh

The message originates in durable-task-plugin, which must be a dependency of one of the plugins.txt plugins.  

Two important observations:

1) The issue does not occur when starting with the base jenkins/jenkins:2.138.2-alpine image and manually installing plugins via UI. That might suggest the issue is around how install-plugins.sh installs plugins and/or dependencies. 

2) The issue does not occur on our production image, which is also 2.138.2-alpine + plugins built 2018-10-11. Rebuilding the the same image from the same Dockerfile results in different installed plugins. Makes me think results using install-plugins.sh are not deterministic.