CMake Custom compiler linker language not found - c++

Question

I try to add a custom compiler to CMake and I have been using this answer to create it: Generic rule from makefile to CMake
When I use enable_languange(MYCOMPILER) this works, but then I have to add also set_target_properties() to be able to compile everything.
I wanted that the user can write his project with just
project(MyProject MYCOMPILER)
The files are copied in a global directory "/opt/amiga/utils/CMake" and the path also includes "/opt/amiga/utils", so CMake is able to find and process the files, which I confirmed by putting message statements in there.
but then I get an error from CMake:
CMake Error: Cannot determine link language for target "MyProject"
So what exactly is required that CMake is recognizing the linking stage as well?
CMakeDetermineAMIGA_CCompiler.cmake
set(AMIGA_COMPILER_NAME $ENV{CC})
if (NOT AMIGA_COMPILER_NAME)
set(AMIGA_COMPILER_NAME m68k-amigaos-gcc)
endif()
find_path(AMIGA_COMPILER_PATH
NAMES
"${AMIGA_COMPILER_NAME}"
"${AMIGA_COMPILER_NAME}.exe"
CMAKE_FIND_ROOT_PATH_BOTH
)
if ("${AMIGA_COMPILER_PATH}" STREQUAL "AMIGA_COMPILER_PATH-NOTFOUND")
message(FATAL_ERROR "'${AMIGA_COMPILER_NAME}' not found. Make sure that '${AMIGA_COMPILER_NAME}' is in PATH!")
endif ("${AMIGA_COMPILER_PATH}" STREQUAL "AMIGA_COMPILER_PATH-NOTFOUND")
# Remove the <path>/bin part
get_filename_component(AMIGA_PATH_PREFIX ${AMIGA_COMPILER_PATH} DIRECTORY)
set(AMIGA_PATH_PREFIX "${AMIGA_PATH_PREFIX}/")
find_program(
AMIGA_COMPILER
NAMES
"${AMIGA_COMPILER_NAME}"
"${AMIGA_COMPILER_NAME}.exe"
HINTS "${AMIGA_COMPILER_PATH}"
DOC "gcc Amiga OS 1.x"
)
if ("${AMIGA_COMPILER}" STREQUAL "AMIGA_COMPILER-NOTFOUND")
message(FATAL_ERROR "'${AMIGA_COMPILER_NAME}' not found. Make sure that '${AMIGA_COMPILER_NAME}[.exe]' is in PATH!")
endif ("${AMIGA_COMPILER}" STREQUAL "AMIGA_COMPILER-NOTFOUND")
mark_as_advanced(CMAKE_${ASM_DIALECT}_COMPILER)
set(CMAKE_AMIGA_C_COMPILER "${AMIGA_COMPILER}")
set(CMAKE_AMIGA_C_SOURCE_FILE_EXTENSIONS c;C;cpp;cxx;CPP;CXX;cc;CC)
set(CMAKE_AMIGA_C_OUTPUT_EXTENSION .o)
set(CMAKE_AMIGA_C_COMPILER_ENV_VAR "CC")
# Configure variables set in this file for fast reload later on
configure_file(${CMAKE_CURRENT_LIST_DIR}/CMakeAMIGA_CCompiler.cmake.in
${CMAKE_PLATFORM_INFO_DIR}/CMakeAMIGA_CCompiler.cmake)
CMakeAMIGA_CInformation.cmake
SET(BUILD_SHARED_LIBS OFF)
set(CMAKE_AMIGA_C_FLAGS "--save-temps -Wall -pedantic -mcrt=nix13 -fno-exceptions -fno-rtti")
set(CMAKE_AMIGA_C_FLAGS_DEBUG "${CMAKE_ASM_FLAGS} -D_DEBUG -g -mregparm")
set(CMAKE_AMIGA_C_FLAGS_RELEASE "${CMAKE_ASM_FLAGS} --O2 -mregparm")
set(CMAKE_INCLUDE_FLAG_AMIGA_C "-I")
if(NOT CMAKE_AMIGA_C_COMPILE_OBJECT)
message(STATUS "Enable AMIGA_C")
set(CMAKE_AMIGA_C_COMPILE_OBJECT "<CMAKE_AMIGA_C_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> <SOURCE>")
endif()
if(NOT CMAKE_AMIGA_C_CREATE_STATIC_LIBRARY)
set(CMAKE_AMIGA_C_CREATE_STATIC_LIBRARY
"<CMAKE_AR> cr <TARGET> <LINK_FLAGS> <OBJECTS> "
"<CMAKE_RANLIB> <TARGET> ")
endif()
if(NOT DEFINED CMAKE_AMIGA_C_ARCHIVE_CREATE)
set(CMAKE_AMIGA_C_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
endif()
if(NOT DEFINED CMAKE_AMIGA_C_ARCHIVE_APPEND)
set(CMAKE_AMIGA_C_ARCHIVE_APPEND "<CMAKE_AR> q <TARGET> <LINK_FLAGS> <OBJECTS>")
endif()
if(NOT DEFINED CMAKE_AMIGA_C_ARCHIVE_FINISH)
set(CMAKE_AMIGA_C_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
endif()
if(NOT CMAKE_AMIGA_C_LINK_EXECUTABLE)
set(CMAKE_AMIGA_C_LINK_EXECUTABLE
"<CMAKE_AMIGA_C_COMPILER> <FLAGS> <CMAKE_AMIGA_C_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
endif()
set(CMAKE_AMIGA_C_INFORMATION_LOADED 1)
CMakeAMIGA_CCompiler.cmake.in
set(CMAKE_AMIGA_C_COMPILER "#CMAKE_AMIGA_C_COMPILER#")
set(CMAKE_AMIGA_C_COMPILER_LOADED 1)
set(CMAKE_AMIGA_C_SOURCE_FILE_EXTENSIONS #CMAKE_AMIGA_C_DIALECT_SOURCE_FILE_EXTENSIONS#)
set(CMAKE_AMIGA_C_OUTPUT_EXTENSION #CMAKE_AMIGA_C_OUTPUT_EXTENSION#)
set(CMAKE_AMIGA_C_COMPILER_ENV_VAR "#CMAKE_AMIGA_C_DIALECT_COMPILER_ENV_VAR#")
CMakeTestAMIGA_CCompiler.cmake
set(CMAKE_AMIGA_C_COMPILER_WORKS 1 CACHE INTERNAL "")
CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(Test AMIGA_C)
set(TARGET ${PROJECT_NAME})
set(SOURCES
main.cpp
)
add_executable(${TARGET} ${SOURCES})