Does the option to Log Xvfb output help? It's in in the advanced settings of the plugin in the job configuration.

I saw this option, but I still have no err messages in log and Xvfb does not mark build as failed.

Code changed in jenkins
User: Zoran Regvart
Path:
src/main/java/org/jenkinsci/plugins/xvfb/XvfbBuildWrapper.java
src/main/resources/org/jenkinsci/plugins/xvfb/Messages.properties
http://jenkins-ci.org/commit/xvfb-plugin/7f2d3b3ae412130a6d90c8a073873c1a5e504c98
Log:
JENKINS-18094 Xvfb plugin doesn't write any error message in build log

Compare: https://github.com/jenkinsci/xvfb-plugin/compare/29e042605ea4...7f2d3b3ae412

I've made the change that fails the build and outputs standard error and standard output to the build console log even if no Xvfb output is wanted (the log Xvfb output checkbox under Advanced) – if the Xvfb process is not alive after starting or after the wait timeout (configurable option). If you find the alive check to be too soon try setting the timeout in seconds to 1-2 seconds.

Also I have increased the requirement for jenkins core, the minimal jenkins version you need to be running to 1.424.6 (LTS of March 2012).

Aleksey, would you mind testing a snapshot version of the plugin, so that I can be sure that this issue is resolved before release?

The snapshot is at: https://dl.dropboxusercontent.com/u/4210293/xvfb-1.0.8-SNAPSHOT.hpi

thanks

Ok, I will test this build, and write down results.

I test it on ~100 builds. Everything is fine )

Thank you very much for reporting and testing this bug. I've released 1.0.8 with the fix outlined in comment 4.

fixed in 1.0.8