readthedocs.org: Error: cannot connect to X server

First, thank you for enabling conda builds on RTD!

I am now trying to build the docs for http://www.glueviz.org using this, and am running into the following error:

Running Sphinx v1.3.1
making output directory...

Installed /home/docs/checkouts/readthedocs.org/user_builds/glueviz/checkouts/latest/doc/.eggs/astropy_helpers-1.1.1-py2.7.egg
/home/docs/checkouts/readthedocs.org/user_builds/glueviz/conda/latest/lib/python2.7/site-packages/matplotlib/font_manager.py:273: UserWarning: Matplotlib is building the font cache using fc-list. This may take a moment.
  warnings.warn('Matplotlib is building the font cache using fc-list. This may take a moment.')
: cannot connect to X server

My readthedocs.yml file contains:

conda:
    file: .environment.yml

python:
    setup_py_install: true

and the .environment.yml contains:


name: glueviz

dependencies:
  - pyqt
  - numpy
  - matplotlib
  - pandas
  - astropy
  - dill
  - h5py
  - scipy
  - scikit-image
  - ipython
  - ipykernel
  - qtconsole
  - traitlets
  - pygments
  - pyzmq
  - mock
  - pytest

I think the cannot connect to X server error occurs when PyQt4 is imported.

On Travis, I normally fix this by doing:

export DISPLAY=:99.0
sh -e /etc/init.d/xvfb start

Is there any way of doing something similar on RTD?

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 16 (3 by maintainers)

Most upvoted comments

FYI for others trying to figure out how to setup headless displays on Read The Docs:

I ran into this issue using sphinx-gallery with vtki to build these examples in our documentation.

Since RTD cannot handle headless displays, I outright switched my projects to deploying from Travis to GitHub pages using doctr: https://github.com/drdoctr/doctr

It works wonderfully and now we have a custom job that builds and deploys the docs on Travis which turns up as a status check on PRs - hope this helps others out there struggling to get RTD to meet their projects’ needs!

Also, I created a ci helper script that can handle setting up all of this on Travis - simply add this to your .travis.yml:

dist: xenial # must use xenial for vtk/vtki

before_install:
  # configure a headless display for vtk/vtki
  - git clone --depth 1 git://github.com/vtkiorg/gl-ci-helpers.git
  - source ./gl-ci-helpers/travis/setup_headless_display.sh

then build your docs and use doctr to deploy!

banesullivan on Apr 24, 2019

Perfect. It does not bypass the setup.cfg. For others, I just created a docs/requirements.txt with a single line

sphinx==1.7.5

and declared docs/requirements.txt in the readthedocs project admin>advanced settings>Requirements file Thank you, readthedocs is great !

ederag on Jun 6, 2018

@ederag you can specify any version of sphinx in your requirements.txt file

stsewd on Jun 6, 2018

Is there any progress on this? I’m trying to build the documentation with some mayavi examples and I need the X server. In travis I just set up a headless server as pointed out in the first post. Is it possible to use it here too?

Titan-C on Jul 3, 2016