ref: d9b37eff37a6d5a0a1ab5c7563ce0818b1d368f5 dir: /sys/lib/python/mercurial/templates/rss/header.tmpl/
<?xml version="1.0" encoding="{encoding}"?> <rss version="2.0"> <channel> <link>{urlbase}{url}</link> <language>en-us</language>