Xorg segfaults when running xrandr with a --scale that isn't 1.0. This is a dual monitor setup and the problem affects both monitors. Using --scale 1.0 works, but this is a no-op since that is the default scale. I'm not sure when the problem started since I don't use --scale very often, but it was within the last few months. Backtrace from /var/log/Xorg.0.log.old: [ 5208.172] (EE) [ 5208.172] (EE) Backtrace: [ 5208.172] (EE) 0: /usr/lib/xorg/Xorg (OsLookupColor+0x135) [0x557816adc345] [ 5208.173] (EE) 1: /lib/x86_64-linux-gnu/libpthread.so.0 (funlockfile+0x50) [0x7fb222ebd200] [ 5208.173] (EE) 2: ? (?+0x0) [0x0] [ 5208.174] (EE) 3: ? (?+0x0) [0x0] [ 5208.174] (EE) [ 5208.174] (EE) Segmentation fault at address 0x0 [ 5208.174] (EE) Fatal server error: [ 5208.174] (EE) Caught signal 11 (Segmentation fault). Server aborting