I am trying to install plugins that's not included in Ikiwiki following instructions at `http://ikiwiki.info/plugins/install/`. So far I tried `http://jblevins.org/git/ikiwiki/plugins.git/plain/h1title.pm` and `http://ikiwiki.info/plugins/contrib/default_content_for___42__copyright__42___and___42__license__42__/`. After putting these `.pm` files in `/home/foo/website/libi/IkiWiki/Plugin` and making them executable, I rebuilt the wiki instance. But the plugins aren't working. 

Any ideas what might be wrong?

Is there some way to debug?