That's not always guaranteed to work. A better approach would be to do something with the ah_bootstrap script, which knows how to import astropy_helpers in all supported cases. But I'm not exactly sure yet how that would work. Something I need to look into. setup.py build_sphinx works.

Readthedocs needs this to work, although as a plan B we can simply add astropy-helpers to the rtd-pip-requirements

That might be more straightforward for now.

@embray - astropy-helpers added to pip requirements for RTD in a1bdf2d

Now that we've gone ahead and included astropy-helpers in the source distribution by default, it should be okay, for all intents and purposes, to do the sys.path insertion for now. One thing that probably won't cooperate with is the auto-update feature, but that's not really intended for developers who would want to build the docs anyways.

Another option would be to install astropy-helpers from the submodule using ./setup.py develop.

Went ahead and pushed the sys.path.insert workaround for now. This shouldn't affect anything else. astropy_helpers should still be listed as one of the docs build requirements. I'll look into a better solution in the future if needed.

Works nicely for me. Travis failures are unrelated. Thanks @embray!