INTERFACE_COMPILE_DEFINITIONS does not work IMPORTED targets:
From 3.6:
Specify compile definitions to use when compiling a given <target>.
The named <target> must have been created by a command such as
add_executable() or add_library() and must not be an Imported Target.
Since 3.11:
Specify compile definitions to use when compiling a given <target>.
The named <target> must have been created by a command such as
add_executable() or add_library() and must not be an ALIAS target.
And this causes the -Wundef warning:
src/Functions/FunctionsHashing.h:1326:5: warning: 'USE_XXHASH' is not defined, evaluates to 0 [-Wundef]