This use case isn't ideal but is probably easier to implement since the top level parent doesn't need to be located and everything to be built is included in the subtree.
The maven-reactor-plugin can be used today to build stuff. We'd like to port at least reactor:resume, reactor:make, reactor:makeDependents into core. I'm thinking it would go something like this:
- -rf --resume-from: Resume reactor from specified project
- -pl --project-list: Build the specified reactor projects instead of all projects
- -am --also-make: If a project list is specified, also make projects that the list depends on
- -amd --also-make-dependents: If a project list is specified, also make projects that depend on projects on the list
- resume: mvn -rf packages/a-package
- make: mvn -am -pl ui/a-ui,ui/b-ui
- makeDependents: mvn -amd -pl packages/a-package,packages/b-package
At least at first, core would not include the new reactor:makeScmChanges because that would require maven-core to depend on maven-scm.