A bunch of CFLAGS had gone missing, so the build failed with errors like:
../../../../../hw/xfree86/os-support/linux/lnx_ev56.c:7:19: error: input.h: No such file or directory
../../../../../hw/xfree86/os-support/linux/lnx_ev56.c:8:24: error: scrnintstr.h: No such file or directory
(cherry picked from commit a1fe36b772)