On Redox relibc defines CLOCK_MONOTONIC=4 (not Linux 1) and has no
CLOCK_MONOTONIC_RAW, so -DCLOCK_MONOTONIC_RAW=4 collided with CLOCK_MONOTONIC in
wsi_common_wayland.c (duplicate case). The greeter uses GL/llvmpipe not Vulkan,
and Vulkan WSI is the only consumer of these Linux clock constants, so disable
vulkan-drivers to drop that unit. Also make the define collision-proof
(CLOCK_MONOTONIC+1000) for any non-Vulkan user.
vasilito
baecdc6d3a