selenium webdriver - Unable to get chrome driver working through jenkins -

i unable chrome driver working via jenkins. tests run fine terminal window wish run them jenkins in headless mode.

i have latest recommended version of chrome driver installed , chrome version 28.0.1500.71. chromedriver has been placed on path @ /usr/bin.

however when attempt run tests jenkins error message:

 "unable either launch or connect chrome. please check chromedriver up-to-date. using chrome binary at: /applications/google chrome.app/contents/macos/google chrome (selenium::webdriver::error::unknownerror)" 

i have tried installing previous version of chrome , chromedriver same error message.

so after investigation found in order run headless tests via jenkins may need have installed xvfb. (i may because not 100% sure if correct) installed xvfb via xquartz , xvfb file on path @ /usr/bin.

however after doing above xvfs still error. xvfs appears start message: xvfb starting$ /usr/bin/xvfb :1 -screen 0 1024x768x24 -fbdir /users/shared/jenkins/home/2013-07-15_16-24-193595155347701391882xvfb in console output in jenkins.

anybody have idea doing wrong? new world of macs there may missing.

any appreciated!!

managed sorted. instead of enabling xvfb in job configuration build environment section, ran using terminal command , works. terminal command now: xvfb-run cucumber --tags @automated - issue can closed