We have an app we don't need to build very often.  When I last worked on it, I spent some time moving it to a Jenkinsfile so we could make use of pipeline. This was working roughly three months ago.  Attempting some updates now and the build phase completes, but no ipa file is created (causing the archive stage to fail as no file matches).

I have the non pipeline build job hanging around, and this still works and creates the IPA file as expected.  I guess the Jenkinsfile parser has changed at some point, and perhaps something in my jenkinsfile is implicitly blocking the creation of the ipa file.