On Debian Stretch using: xcalib -i -a results in Error - unsupported ramp size 0 It is in some cases used for Accessibillity A11y needs. It was discussed here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=851810 There seems to be a Patch here: https://lists.x.org/archives/xorg-devel/2017-October/054991.html
Patch was merged as https://cgit.freedesktop.org/xorg/xserver/commit/?id=ac138f9b31b0fba00742edbc3326afe66e28099a.
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