COLLECTD_PLUGINS is listed as a USE_EXPAND variable but has no corresponding collectd_plugins.desc file. After addition of that file, app-admin/collectd/metadata.xml should be cleaned of local collectd_plugins_* flag descriptions.
This is now corrected: > commit 91273049a72fe478a8207be6cfda8e1638ab95aa > Author: Thomas Deutschmann > Date: Mon Sep 26 00:31:50 2016 +0200 > > app-admin/collectd: Move collectd_plugins_* flags from metadata.xml to collectd_plugins.desc > > Gentoo-Bug: https://bugs.gentoo.org/588250 > > Package-Manager: portage-2.3.1