ref: dbfec06bf1f8de922ca3af09d14675ef44ada5d2
dir: /sys/lib/python/mercurial/templates/rss/error.tmpl/
{header} <title>Error</title> <description>Error</description> <item> <title>Error</title> <description>{error|escape}</description> <guid>http://mercurial.selenic.com/#error</guid> </item> </channel> </rss>