This fails because #5292 hasn't been merged back into master from 1.5.x

Ok. I'll do the merge.

Linkchecker is not python 3 compatible 😞

Bummer. Since linkchecker doesn't actually have to run in the same Python as the docs build, though, I wonder if we could just install it from the Debian package. I might as well try that here.

It seems linkchecker is not in the Travis APT installable whitelist. It's been requested, I think it just needs a human from Travis to manually verify that it's safe: travis-ci/apt-package-safelist#1187

We could try to install and run linkchecker in the Python 2.7 install alongside building the docs in 3.5, but that could get hairy...

If we used conda we could just make two envs.....

It looks like linkchecker is making progress on python3 compatibility on their master branch, probably not worth the effort though.

We can do that with virtualenv too if we want to something like

deactivate
source ~/virtualenv/python2.7/bin/activate
pip install linkchecker

But I don't know how brittle that will be.

Closed since #5797 is merged