plugins/maven-plugin/blockTriggerWhenBuilding.html

<div>
    <p>
        By default when a newer build of an upstream project is building (or in queue),
        an earlier build will not trigger builds of downstream modules.
        This is under the assumption that those builds would soon be superseded and are not of interest.
    </p>
    <p>
        You can however disable this logic on the upstream project, which will result in a fuller sequence of downstream builds.
        This is not be confused with <b>Block build when upstream project is building</b> (marked on the other project),
        which controls <em>scheduling</em> of the downstream project once it has been triggered.
    </p>
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