RE: our thread in the Hugo issues, I wanted to see if I could see how you were getting hugo.
Using go get -u -v github.com/spf13/hugo is going to get the latest version of hugo on master, which means it could be wildly different from the last time you built your site with the version of hugo you use.
I would recommend installing a stable tarball that you know is unchanged, like this:
root@localhost:/usr/local/hugo-site/examples/rahulrai.in# hugo --source=. --destination=export
Started building sites ...
ERROR 2017/04/16 06:38:26 Error while rendering "page": template: _default/single.html:3:3: executing "_default/single.html" at <partial "head.html" ...>: error calling partial: template: partials/head.html:16:86: executing "partials/head.html" at <.RSSlink>: can't evaluate field RSSlink in type *hugolib.PageOutput
root@localhost:/usr/local/hugo-site/examples/rahulrai.in#