Selenium Error: no display specified


I’ve installed selenium-server-standalone-2.42.2.jar in a debian virtual box

and installed Firefox 29.0

and trying to run the following script with phpunit which is the only file in the directory:

class TestLogin extends PHPUnit_Extensions_Selenium2TestCase{
public function setUp()
public function testHasLoginForm()
$username = $this->byName('username');
$password = $this->byName('password');
$this->assertEquals('', $username->value());
$this->assertEquals('', $password->value());

I get the following error:

1) TestLogin::testHasLoginForm
PHPUnit_Extensions_Selenium2TestCase_WebDriverException: Unable to connect to host on port 7055 after 45000 ms. Firefox console output:
Error: no display specified
Error: no display specified

What does this mean?

I’ve red several threads and apparently I had to do the following which I tried:

1)to type this in the command shell

export PATH=:0;

Result: I got the same error.

2) I’ve installed vnc4server and getting debian-vm:1 as a application I then set export PATH=debian-vm:1 run it with realvnc and in the viewer (which works) I got the same problem.

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You receive this error, because you have not set the DISPLAY variable. Here is a guide how to perform the test on a headless machine.

You have to install Xvfb and a browser first:

apt-get install xvfb
apt-get install firefox-mozilla-build

then start Xvfb:

Xvfb &

set DISPLAY and start Selenium:

export DISPLAY=localhost:0.0
java -jar selenium-server-standalone-2.44.0.jar

and then you will be able to run your tests.

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