CMake on aarch64 systems.

[gampUMKC]

In CMakeLists.txt
the following code checks for 32 bit arm systems.

if (UNIX AND NOT APPLE)
if (CMAKE_SYSTEM_PROCESSOR MATCHES "arm|ARM")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=neon")
else()
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -msse4.1")
endif()
endif()

A fix would be to add another line such as

else if (CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64")
endif()

It shouldn't require any additional flags since neon is mandatory for aarch64, and both the -mfpu=neon and -msse4.1 flags cause cmake to fail.