ref: 0c2cc473a7e0c6704a5a6a89019d62a67f6e5e82 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>