+ " is missing.",
                    dependency.getLocation(""));
            return null;
        }

        String imported = groupId + ':' + artifactId + ':' + version;

        if (importIds.contains(imported)) {
            StringBuilder message =
                    new StringBuilder("The dependencies of type=pom and with scope=import form a cycle: ");

            PluginDescriptor pluginDescriptor = null;
            if (plugin.isExtensions() && !artifacts.isEmpty()) {
                // ignore plugin descriptor parsing errors at this point
                // these errors will reported during calculation of project build execution plan
                try {
                    pluginDescriptor = extractPluginDescriptor(artifacts.get(0), plugin);

                            errOn30,
                            Version.V20,
                            prefix + prefix2 + "classifier",
                            key,
                            "must be empty, imported POM cannot have a classifier.",
                            dependency);
                }
            } else if ("system".equals(dependency.getScope())) {