Tag Archives: QXcbConnection: Could not connect to display

Installing CasperJS on Raspberry Pi

This is generally a simple process to install CapserJS on a *NIX box, but had not done this on a Raspberry Pi before, and ran into a couple of minor gotchas. This is a stripped down explanation of what I needed to do, but it will server as a reference for me, and maybe for some other people as well.

Prerequisites for installing CapserJS

  • Node
  • npm
  • PhantomJS

Node

Installing node is very simple, but you should grab root access to do it. This should be simple and run without any issues.

apt-get install nodejs


npm

The Node Package Manager will be used later to actually install CasperJS, once PhantomJS has been successfully installed.

apt-get install npm


PhantomJS

PhantomJS is a web automation framework, that CasperJS uses to run it’s extended suite of tools. NOTE. I found that I needed to modify my user’s (pi in this case) environment to tell Phantom that not to expect a console for rendering webpages; I’ll document that at the bottom.

apt-get install phantomjs


CasperJS

Installing CasperJS is done most simply via the npm (Node Package Manager):

npm install -g casperjs


Handling the PhantomJS Display Error

pi@raspberrypi:~ $ casperjs
QXcbConnection: Could not connect to display
PhantomJS has crashed. Please read the bug reporting guide at
and file a bug report.
Aborted

The fix is to add this line to the .bashrc file, which will stop the error. I simply added this to the last line of the file.

export QT_QPA_PLATFORM=offscreen