Karl Shultz noticed an anomaly in the Plugin Manager. Looking into https://updates.jenkins-ci.org/update-center.actual.json I found that most Pipeline plugins specified excerpt="", despite having an index.jelly, because they have no <description> in the POM; but the recently released incrementalified workflow-api has

"excerpt": "The Jenkins Plugins Parent POM Project"

This is because the workflow-api.hpi!/META-INF/maven/org.jenkins-ci.plugins.workflow/workflow-api/pom.xml specified

<description>The Jenkins Plugins Parent POM Project</description>

due to it using flatten-maven-plugin. Now backend-update-center2 reads pom.xml#/project/description and sets that to the excerpt, which is wrong because it ignores the parent POM, though we did not notice that before; and because lots of plugins just omit a POM description in favor of the index file. At runtime, index.jelly is preferred by PluginManager/installed.jelly, but PluginManager/table.jelly used by the Updates tab only checks the excerpt.