@Nonnull
	public ModularClassPath resolveClassPath() {
		if (mcp == null) {
			DependencyResolver resolver = new DependencyResolver();
			project.updateDependencyResolver(resolver);
			for (Project prj : project.getSubProjects()) {
				prj.updateDependencyResolver(resolver);
				resolver.addClassPath(forSubProject(prj).getJarFile().toAbsolutePath().toString());
			}
			mcp = resolver.resolve();
		}
		return mcp;
	}
Determines if the associated jar is up-to-date, returns false if it needs to
be rebuilt
src/main/java/dev/jbang/source/BuildContext.java