ref: 347bb2a7a7110e55debd5ebe57ba03bbe315c5ba
dir: /sys/src/cmd/hg/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>