:) However, having an X server running and other X apps displaying their UI on the local machine, I thought there's no risk of not having fontconfig properly installed locally.
Also installed fonts on the remote machine. I still get the same error:
Fontconfig warning: line 32: unknown element "cachedir"
Fontconfig warning: line 33: unknown element "cachedir"
Fontconfig...
a workstation with an X server
a CentOS server with no X server installed (development, security is not a concern)
a GUI application installed on the server