The links here in the photutils docs are broken:
http://photutils.readthedocs.org/en/latest/photutils/aperture.html#class-inheritance-diagram

E.g. clicking on "CircularAperture" leads to
http://photutils.readthedocs.org/en/api/photutils.aperture_core.CircularAperture.html#photutils.aperture_core.CircularAperture
which results in a page saying "error: doesn't exist".

@bsipocz - A known issue?