L ~ : lightdm --test-mode
Running inside an X server requires Xephyr to be installed but it cannot be found. Please install it or update your PATH environment variable.
L ~ : cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=15.10
DISTRIB_CODENAME=wily
DISTRIB_DESCRIPTION="Ubuntu 15.10"
Got exactly the same.
L ~ : lightdm --test-mode RELEASE= 15.10 CODENAME= wily DESCRIPTION= "Ubuntu 15.10"
Running inside an X server requires Xephyr to be installed but it cannot be found. Please install it or update your PATH environment variable.
L ~ : cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_
DISTRIB_
DISTRIB_