darktable-chart -V (return code: 1)
Unable to init server: Could not connect: Connection refused
(darktable-chart:25061): Gtk-WARNING **: cannot open display:
darktable-chart --help (return code: 1)
Usage: darktable-chart [<input Lab pfm file>] [<cht file>] [<reference cgats/it8 or Lab pfm file>]
darktable-chart --csv <csv file> <number patches> <output dtstyle file>