Fix warnings in the documentation build

.travis.yml

@@ -18,6 +18,8 @@ script:
 - if [ ${REPO_TYPE} == "r" ]; then cd tests && travis_wait pytest --cov repo2docker
   -v ${REPO_TYPE}; else cd tests && travis_retry pytest --cov repo2docker -v ${REPO_TYPE};
   fi
+- pip install -r docs/doc-requirements.txt
+- cd docs && make html
 after_success:
 - pip install codecov
 - codecov

docs/Makefile

@@ -2,7 +2,7 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    =
+SPHINXOPTS    = -W
 SPHINXBUILD   = python3 -msphinx
 SPHINXPROJ    = repo2docker
 SOURCEDIR     = source

docs/source/deploy.rst

@@ -1,4 +1,4 @@
-.. _usage:
+.. _deploy:
 
 Using ``repo2docker`` as part of your Continuous Integration
 ============================================================

docs/source/install.rst

@@ -57,19 +57,19 @@ Bash on Windows) provides additional information about Windows and docker.
 
 .. _using Windows and the WSL: https://nickjanetakis.com/blog/setting-up-docker-for-windows-and-wsl-to-work-flawlessly
 
-.. _jupyterhub:
+.. _jupyterhub_ready:
 
 JupyterHub-ready images
 -----------------------
 
-`JupyterHub <https://jupyterhub.readthedocs.io/en/stable/>`_ allows multiple
+JupyterHub_ allows multiple
 users to collaborate on a shared Jupyter server. ``repo2docker`` can build
 Docker images that can be shared within a JupyterHub deployment.  For example,
 `mybinder.org <https://mybinder.org>`_ uses JupyterHub and ``repo2docker``
 to allow anyone to build a Docker image of a git repository online and
 share an executable version of the repository with a URL to the built image.
 
-To build `JupyterHub <https://github.com/jupyterhub/jupyterhub>`_-ready
+To build JupyterHub_-ready
 Docker images with ``repo2docker``, the version of your JupterHub deployment
 must be included in the ``environment.yml`` or ``requiements.txt`` of the
 git repositories you build.
@@ -79,3 +79,5 @@ command to run ``jupyterhub-singleuser`` by adding this line in your
 configuration file::
 
   c.DockerSpawner.cmd = ['jupyterhub-singleuser']
+
+.. _JupyterHub: https://github.com/jupyterhub/jupyterhub

docs/source/usage.rst

@@ -21,7 +21,7 @@ repo2docker is called with this command::
 where ``<URL-or-path to repo>`` is a URL or path to the source repository.
 
 For example, use the following to build an image of Peter Norvig's
-`Pytudes <https://github.com/norvig/pytudes/>`_::
+Pytudes_::
 
   jupyter-repo2docker https://github.com/norvig/pytudes
 
@@ -47,12 +47,14 @@ Python 3.6 unless you include the version of Python in your
 Python 2.7, 3.5, and 3.6.  In the case of this repo, a Python version is not
 specified in their configuation files and Python 3.6 is installed.
 
-`Pytudes <https://github.com/norvig/pytudes>`_
+Pytudes_
 uses a `requirements.txt file <https://github.com/norvig/pytudes/blob/master/requirements.txt>`_
 to specify its Python environment. ``repo2docker`` uses ``pip`` to install
 dependencies listed in the ``requirement.txt`` in the image. To learn more about
 configuration files in ``repo2docker`` visit :ref:`config-files`.
 
+.. _Pytudes: https://github.com/norvig/pytudes
+
 When the image is built, a message will be output to your terminal::
 
   Copy/paste this URL into your browser when you connect for the first time,