QXcbConnection: Could not connect to display

[arrmo]

1. Which version of PhantomJS are you using? Tip: run phantomjs --version.
   2.1.1
2. What steps will reproduce the problem?
   1. Take a working javascript file (e.g. rasterize.js)
   2. Call the file from a script file (e.g. executable file, #!/bin/sh at the start)
   3. Now execute the script file as a cron job
3. Which operating system are you using?
   Ubuntu 16.04 LTS
4. Did you use binary PhantomJS or did you compile it from source?
   Binary - installed it as part of Ubuntu (using apt).
5. Please provide any additional information below.
   This is very similar to QXcbConnection: Could not connect to display #14240, but I am using the stock version of PhantomJS (with Ubuntu). Below is the output from running the cron job (which calls the script file, to generate a pdf file once a day) ...

QXcbConnection: Could not connect to display
PhantomJS has crashed. Please read the bug reporting guide at
http://phantomjs.org/bug-reporting.html and file a bug report.
Aborted (core dumped)

Thanks!

[vitallium]

Please check your environment variable QT_QPA_PLATFORM. It must be empty.

[arrmo]

Yep, it is - in both cases. Does this need to be manually forced for some reason?

Thanks!

[zackw]

I would send a patch to reset all the troublesome environment variables before initializing Qt ... if I could find a list of them anywhere.

But it sounds like this isn't actually the problem?

[arrmo]

It doesn't sound like it, but I could definitely be wrong.

[arrmo]

Trying different things, no luck. Is there a setting of QT_QPA_PLATFORM that you believe may help?

Thanks!

[ricohumme]

Hi,

Having same issue here.
Working with 1.9 on my dev machine, works fine.
But on the live server I can't even download 1.9.x so I'm stuck now.

Where can I find this settings of QT? How to get there. So I can check that on my side.

Thanks!

[jglogan]

The offscreen platform is a usable workaround for me with the stock Ubuntu package. This works for me:

QT_QPA_PLATFORM=offscreen phantomjs rasterize.js 2i8zaNg04d9B41Zir2kT3J/output.html 2i8zaNg04d9B41Zir2kT3J.png

[oiwn]

can confirm export QT_QPA_PLATFORM=offscreen before selenium scripts work's well.

[ricohumme]

We finally got things working by downloading the binary at https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2 and extracting the phantomjs to /usr/bin

[oiwn]

I had hard times with ubuntu 16.04 they basically distribute half finished system with lots of broken packages.

[ricohumme]

I'm running on 16.04 too, but the problem with the repo's is that they deliver with x11, which fails. So with the binary I don't have that issue and it works perfectly now.

[arrmo]

Works here now also - thanks!!!

[ariya]

Debian/Ubuntu has a modified version of PhantomJS that can work headlessly, hence the problem with QXcb. See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817277 for details.

Unfortunately, this is not something that we (=PhantomJS team) can fix.

[3zzy]

@ricohumme Can you provide the steps (commands) to install it? I tried:

export PHANTOM_JS_VERSION=2.1.1
wget "https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-$PHANTOM_JS_VERSION-linux-x86_64.tar.bz2"
tar xvfj "./phantomjs-$PHANTOM_JS_VERSION-linux-x86_64.tar.bz2"
ln -sf "./phantomjs-$PHANTOM_JS_VERSION-linux-x86_64/bin/phantomjs" "/usr/bin"

but still couldn't get it working

[ricohumme]

@3zzy the steps I used are as follows:
wget https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2
bzip2 -d phantomjs-2.1.1-linux-x86_64.tar.bz2
tar -xvf phantomjs-2.1.1-linux-x86_64.tar
cp phantomjs-2.1.1-linux-x86_64/bin/phantomjs /usr/bin/phantomjs

Does this help your case?

[HideoKun]

Thanks for help, solution above works well :)

[elhamdaoui]

I have the same error but in Odoo

[seachanged]

xvfb-run worked best for me, from Ariya's link posted 8/2016.
xvfb is "providing an unobtrusive way to run applications that don’t really need an X server but insist on having one anyway."

[michaelkl]

@jglogan Thank you for solution with QT_QPA_PLATFORM=offscreen. It let me run phantomjs itself, but it was failing for me with EOFError: end of file reached message on certain pages.
After some experiments with different platforms I found out that it works like a charm with QT_QPA_PLATFORM=minimal.
Hope this will help someone.

[Dingo64]

It seems that QT_QPA_PLATFORM=offscreen is not perfect. It works on Debian 8 jessie amd64 with PhantomJS 2.1.1 when you want to show version info:

# QT_QPA_PLATFORM=offscreen phantomjs --version
2.1.1

but it fails when you try to, for example, render a website:

[FATAL] QFontDatabase: Cannot find font directory /usr/lib/x86_64-linux-gnu/fonts - is Qt installed correctly?

So I just extracted phantomjs binary from https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2 and this one works great.

To be honest most of the binaries on my server are from archives like this. The ones installed with apt-get often doesn't work (like phantomjs), are outdated or contain a lot of unnecessary files.

[ip1981]

Debian/Ubuntu has a modified version of PhantomJS that can work headlessly, hence the problem with QXcb. See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=817277 for details.

This is quite the opposite:

Unfortunately it can not be fixed in Debian. To achieve headless-ness
upstream statically link with customised QT + Webkit. We don't want to ship
forks of those projects. It would be great to eventually convince upstream to
use standard libraries.

There is also a suggestion to use xvfb-run, which is right.

[eunick]

try to uninstall phantomjs and just download the binary then create the softlink. that works for me..

apt-get remove phantomjs
ln -s /opt/phantomjs-2.1.1-linux-x86_64/bin/phantomjs /usr/local/bin/phantomjs

[fuzzygroup]

I can absolutely confirm what ricohumme said:

We finally got things working by downloading the binary at https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2 and extracting the phantomjs to /usr/bin

What we found was that without this specific version of phantomjs on Ubuntu 16, no text would appear in the rendered pdf files. We ran it as:

QT_QPA_PLATFORM=phantom QT_QPA_FONTDIR=/usr/share/fonts phantomjs ../vendor/assets/javascripts/rasterize.js file.html file.pdf letter

And that successfully rendered a pdf.

[jorgesinval]

Every time I try to plot anything with RStudio Cloud using the webshot package I obtain an error. An example:

#install webshot
library(webshot)
webshot::install_phantomjs()
# Make the graph
my_graph=wordcloud2(demoFreq, size=1.5)
# save it in html
library("htmlwidgets")
saveWidget(my_graph,"tmp.html",selfcontained = F)
# and in png
webshot("tmp.html","fig_1.png", delay =5, vwidth = 480, vheight=480)

The error says:

QXcbConnection: Could not connect to display :0
PhantomJS has crashed. Please read the bug reporting guide at
<http://phantomjs.org/bug-reporting.html> and file a bug report.
Error in webshot("tmp.html", "fig_1.png", delay = 5, vwidth = 480, vheight = 480) : 
  webshot.js returned failure value: -6

Any thoughts?