If the GPX2 visualizer is run on a headless box (no DISPLAY) it will stop with an error message:
% gpx2 --help
gpx2: cannot connect to X server
This means that the automatic generation of prediction pictures will fail.
One way to mitigate this is by using a virtual frame buffer that emulates an X-server (Xvfb):
% xvfb-run gpx2 --help
############################################################################### # GPX2 - Global Phasing image and prediction visualizer # ############################################################################### ...
For a full autoPROC processing run the following command should be used:
% xvfb-run process ...
On CentOS/RHEL based machines the required software can be installed (as root):
% yum install xorg-x11-server-Xvfb.x86_64
