This was an upstream issue due to new work in the vulkan driver that uses newer libxcb functions (only in 1.13+).
For Mesa 18.2.1, the following upstream commit resolves the build issue:
dd333c66bdcb11c0d7c5 "vulkan: Disable randr lease for libxcb < 1.13"
Hopefully this should make it into Mesa 18.2.2 shortly.
--
Stuart Young (aka Cefiar)