I already fixed it - https://phabricator.haskell.org/D2470 .

On 24 August 2016 at 00:39, Ben Gamari <ben@smart-cactus.org> wrote:
Harendra Kumar <harendra.kumar@gmail.com> writes:

> I got to the bottom of the problem after some debugging. The short summary
> is - I was using "devel2" flavor which disables doc targets. The problem
> was it only disables them partially not fully. So even though I was able to
> invoke the targets I got these errors and the guide is mostly built except
> for the flags refs.
>
Good sleuthing!

I suppose the Sphinx html targets should simply fail with an error when
BUILD_SPHINX_HTML is not set. The right place to fix this is likely
rules/sphinx.mk if you are interested in fixing this.

Cheers,

- Ben