Some Linux stock images (like ami-bba0fede) have the following script: /usr/local/bin/Xvfb
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.
- Try to run xvfb-run:
It will hang.
Add a line to the Startup Script to remove that script
Customize the image, removing the script