Fix rtd build and be more strict about builds (fail on warn).

Readthedocs was silently just ignoring many errors and for exampel not
including .. automodule: when they couldn't be imported and not
rendering anything within the `.. ipython::` directive.

Make it work (and fail if it ever break again).

docs/environment.yml

@@ -1,11 +1,14 b''
 name: ipython_docs
 dependencies:
 - python=3.6
 - setuptools>=18.5
 - sphinx>=1.8
 - sphinx_rtd_theme
+- numpy
+- nose
+- testpath
+- matplotlib
 - pip:
     - docrepr
     - prompt_toolkit
-    - ipython
     - ipykernel

docs/source/conf.py

@@ -1,300 +1,296 b''
 # -*- coding: utf-8 -*-
 #
 # IPython documentation build configuration file.
 
 # NOTE: This file has been edited manually from the auto-generated one from
 # sphinx.  Do NOT delete and re-generate.  If any changes from sphinx are
 # needed, generate a scratch one and merge by hand any new fields needed.
 
 #
 # This file is execfile()d with the current directory set to its containing dir.
 #
 # The contents of this file are pickled, so don't put values in the namespace
 # that aren't pickleable (module imports are okay, they're removed automatically).
 #
 # All configuration values have a default value; values that are commented out
 # serve to show the default value.
 
 import sys, os
 
 # http://read-the-docs.readthedocs.io/en/latest/faq.html
 ON_RTD = os.environ.get('READTHEDOCS', None) == 'True'
 
 if ON_RTD:
     tags.add('rtd')
 
     # RTD doesn't use the Makefile, so re-run autogen_{things}.py here.
     for name in ('config', 'api', 'magics', 'shortcuts'):
         fname = 'autogen_{}.py'.format(name)
         fpath = os.path.abspath(os.path.join('..', fname))
         with open(fpath) as f:
             exec(compile(f.read(), fname, 'exec'), {
                 '__file__': fpath,
                 '__name__': '__main__',
             })
 else:
     import sphinx_rtd_theme
     html_theme = "sphinx_rtd_theme"
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # If your extensions are in another directory, add it here. If the directory
 # is relative to the documentation root, use os.path.abspath to make it
 # absolute, like shown here.
 sys.path.insert(0, os.path.abspath('../sphinxext'))
 
 # We load the ipython release info into a dict by explicit execution
 iprelease = {}
 exec(compile(open('../../IPython/core/release.py').read(), '../../IPython/core/release.py', 'exec'),iprelease)
 
 # General configuration
 # ---------------------
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.autosummary',
     'sphinx.ext.doctest',
     'sphinx.ext.inheritance_diagram',
     'sphinx.ext.intersphinx',
     'sphinx.ext.graphviz',
     'IPython.sphinxext.ipython_console_highlighting',
     'IPython.sphinxext.ipython_directive',
     'sphinx.ext.napoleon',  # to preprocess docstrings
     'github',  # for easy GitHub links
     'magics',
     'configtraits',
 ]
 
-if ON_RTD:
-    # Remove extensions not currently supported on RTD
-    extensions.remove('IPython.sphinxext.ipython_directive')
-    extensions.remove('IPython.sphinxext.ipython_console_highlighting')
-
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
 # The suffix of source filenames.
 source_suffix = '.rst'
 
 rst_prolog = ''
 
 def is_stable(extra):
     for ext in {'dev', 'b', 'rc'}:
         if ext in extra:
             return False
     return True
 
 if is_stable(iprelease['_version_extra']):
     tags.add('ipystable')
     print('Adding Tag: ipystable')
 else:
     tags.add('ipydev')
     print('Adding Tag: ipydev')
     rst_prolog += """
 .. warning::
 
     This documentation covers a development version of IPython. The development
     version may differ significantly from the latest stable release.
 """
 
 rst_prolog += """
 .. important::
 
     This documentation covers IPython versions 6.0 and higher. Beginning with
     version 6.0, IPython stopped supporting compatibility with Python versions
     lower than 3.3 including all versions of Python 2.7.
 
     If you are looking for an IPython version compatible with Python 2.7,
     please use the IPython 5.x LTS release and refer to its documentation (LTS
     is the long term support release).
 
 """
 
 # The master toctree document.
 master_doc = 'index'
 
 # General substitutions.
 project = 'IPython'
 copyright = 'The IPython Development Team'
 
 # ghissue config
 github_project_url = "https://github.com/ipython/ipython"
 
 # numpydoc config
 numpydoc_show_class_members = False # Otherwise Sphinx emits thousands of warnings
 numpydoc_class_members_toctree = False
+warning_is_error = True
 
 # The default replacements for |version| and |release|, also used in various
 # other places throughout the built documents.
 #
 # The full version, including alpha/beta/rc tags.
 release = "%s" % iprelease['version']
 # Just the X.Y.Z part, no '-dev'
 version = iprelease['version'].split('-', 1)[0]
 
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
 #today = ''
 # Else, today_fmt is used as the format for a strftime call.
 today_fmt = '%B %d, %Y'
 
 # List of documents that shouldn't be included in the build.
 #unused_docs = []
 
 # Exclude these glob-style patterns when looking for source files. They are
 # relative to the source/ directory.
 exclude_patterns = []
 
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
 #add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
 #add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
 #show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
 # Set the default role so we can use `foo` instead of ``foo``
 default_role = 'literal'
 
 # Options for HTML output
 # -----------------------
 
 # The style sheet to use for HTML and HTML Help pages. A file of that name
 # must exist either in Sphinx' static/ path, or in one of the custom paths
 # given in html_static_path.
 # html_style = 'default.css'
 
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
 #html_title = None
 
 # The name of an image file (within the static path) to place at the top of
 # the sidebar.
 #html_logo = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
 
 # Favicon needs the directory name
 html_favicon = '_static/favicon.ico'
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
 html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 #html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
 #html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
 html_additional_pages = {
     'interactive/htmlnotebook': 'notebook_redirect.html',
     'interactive/notebook': 'notebook_redirect.html',
     'interactive/nbconvert': 'notebook_redirect.html',
     'interactive/public_server': 'notebook_redirect.html',
 }
 
 # If false, no module index is generated.
 #html_use_modindex = True
 
 # If true, the reST sources are included in the HTML build as _sources/<name>.
 #html_copy_source = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
 #html_use_opensearch = ''
 
 # If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
 #html_file_suffix = ''
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'ipythondoc'
 
 intersphinx_mapping = {'python': ('https://docs.python.org/3/', None),
                        'rpy2': ('https://rpy2.readthedocs.io/en/version_2.8.x/', None),
                        'traitlets': ('https://traitlets.readthedocs.io/en/latest/', None),
                        'jupyterclient': ('https://jupyter-client.readthedocs.io/en/latest/', None),
                        'ipyparallel': ('https://ipyparallel.readthedocs.io/en/latest/', None),
                        'jupyter': ('https://jupyter.readthedocs.io/en/latest/', None),
                        'jedi': ('https://jedi.readthedocs.io/en/latest/', None),
                        'traitlets': ('https://traitlets.readthedocs.io/en/latest/', None),
                        'ipykernel': ('https://ipykernel.readthedocs.io/en/latest/', None),
                        'prompt_toolkit' : ('https://python-prompt-toolkit.readthedocs.io/en/stable/', None),
                        'ipywidgets': ('https://ipywidgets.readthedocs.io/en/stable/', None),
                        'ipyparallel': ('https://ipyparallel.readthedocs.io/en/stable/', None)
                       }
 
 # Options for LaTeX output
 # ------------------------
 
 # The paper size ('letter' or 'a4').
 latex_paper_size = 'letter'
 
 # The font size ('10pt', '11pt' or '12pt').
 latex_font_size = '11pt'
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, document class [howto/manual]).
 
 latex_documents = [
     ('index', 'ipython.tex', 'IPython Documentation',
      u"""The IPython Development Team""", 'manual', True),
     ('parallel/winhpc_index', 'winhpc_whitepaper.tex',
      'Using IPython on Windows HPC Server 2008',
      u"Brian E. Granger", 'manual', True)
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
 #latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
 #latex_use_parts = False
 
 # Additional stuff for the LaTeX preamble.
 #latex_preamble = ''
 
 # Documents to append as an appendix to all manuals.
 #latex_appendices = []
 
 # If false, no module index is generated.
 latex_use_modindex = True
 
 
 # Options for texinfo output
 # --------------------------
 
 texinfo_documents = [
   (master_doc, 'ipython', 'IPython Documentation',
    'The IPython Development Team',
    'IPython',
    'IPython Documentation',
    'Programming',
    1),
 ]
 
 modindex_common_prefix = ['IPython.']
 
 
 # Cleanup
 # -------
 # delete release info to avoid pickling errors from sphinx
 
 del iprelease