Just updated some plugins and found some Maven projects not loading due to
java.lang.NullPointerException
at hudson.plugins.emailext.EmailExtTemplateActionFactory.createFor(EmailExtTemplateActionFactory.java:27)
at hudson.model.AbstractProject.createTransientActions(AbstractProject.java:761)
at hudson.maven.AbstractMavenProject.createTransientActions(AbstractMavenProject.java:179)
at hudson.maven.MavenModuleSet.createTransientActions(MavenModuleSet.java:465)
at hudson.model.AbstractProject.updateTransientActions(AbstractProject.java:751)
at hudson.maven.MavenModuleSet.updateTransientActions(MavenModuleSet.java:461)
at hudson.model.AbstractProject.onLoad(AbstractProject.java:338)
at hudson.maven.MavenModuleSet.onLoad(MavenModuleSet.java:791)
Seems like https://github.com/jenkinsci/email-ext-plugin/commit/6f5dd8ff0f6e665f33e909bc3ac4d75bb2a38fc8 is newly asking for getPublishersList, and in MavenModuleSet.createTransientActions this might temporarily be null, as a comment warns—after the place where this NPE is being thrown.
It is just not allowed to return null from this method. The implementation in Project in core gets around this (JENKINS-18589) using an atomic field updater.
A temporary workaround in Email Ext would be to check for null here.