[trac1018] as jeremy noted, should be += of course

src/bin/cfgmgr/plugins/Makefile.am

@@ -4,4 +4,4 @@ EXTRA_DIST += logging.spec b10logging.py
 
 config_plugindir = @prefix@/share/@PACKAGE@/config_plugins
 config_plugin_DATA = tsig_keys.py tsig_keys.spec
-config_plugin_DATA = b10logging.py logging.spec
+config_plugin_DATA += b10logging.py logging.spec