Summary

Some Linux stock images (like ami-bba0fede) have the following script: /usr/local/bin/Xvfb

#!/bin/sh
/usr/bin/Xvfb -listen tcp $@

However, since xvfb-run relies on executing off an Xvfb process and waiting on a SIGUSR1 signal from Xvfb to proceed, this wrapper script breaks it, as the signal gets to this script but not all the way back to xvfb-run.

The xvfb-run is hanging because of that.

Steps to Reproduce

1. Try to run xvfb-run:

Expected Results

It works.

Actual Results

It will hang.

Workaround

Workaround 1
Add a line to the Startup Script to remove that script

Workaround 2
Customize the image, removing the script