In Jenkins, when you unstash a named stash, the stash must exist or
else you will get an error. So, how can you cope with this? Sure,
one way is to catch the exception that is raised, but there is yet
another way that you can make this work. When storing a stash, add
the option allowEmpty: true.
20200114/DuckDuckGo jenkins unstash no such stash
20200114/DuckDuckGo jenkins unstash no such stash no files to stash
20200114/https://issues.jenkins-ci.org/browse/JENKINS-52361
20200114/DuckDuckGo jenkins unstash allowEmpty
20200114/https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#stash-stash-some-files-to-be-used-later-in-the-build