Detect overriding of an existing signature and exit early saying to use -codesign

CODE SIGNING: process 86140[app]: rejecting invalid page at address 0x104324000 from offset 0x0 in file "~/small_app_and_lib_signed/build/app.app/Contents/Frameworks/Core.framework/Versions/A/Core" (cs_mtime:1647280809.427209526 == mtime:1647280809.427209526) (signed:1 validated:1 tainted:1 nx:0 wpmapped:0 dirty:0 depth:0)

cmake_minimum_required(VERSION 3.16)
project(proj)
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)

file(GENERATE OUTPUT "core.cpp" CONTENT "\
int foo() { return 0; }")

add_library(Core SHARED core.cpp)
set_target_properties(Core PROPERTIES
    FRAMEWORK 1
    LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/app.app/Contents/Frameworks"
)

file(GENERATE OUTPUT "main.cpp" CONTENT "\
extern int foo();
int main(int, char**) {
    int a = foo();
    return 0;
}")

add_executable(app MACOSX_BUNDLE main.cpp)
target_link_libraries(app PRIVATE Core)

set(core_path ${CMAKE_BINARY_DIR}/app.app/Contents/Frameworks/Core.framework/Core)
add_custom_target(clean_rpath ALL
    COMMAND sh -c
            "install_name_tool -delete_rpath foo ${core_path} || /usr/bin/true"
    VERBATIM
)
add_dependencies(clean_rpath Core app)
add_custom_target(sign ALL
    COMMAND codesign -vvv --sign - --force
            "${CMAKE_BINARY_DIR}/app.app/Contents/Frameworks/Core.framework/Core"
    VERBATIM
)
add_dependencies(sign clean_rpath)
add_custom_target(modify ALL
    COMMAND sh -c
            "install_name_tool -add_rpath foo ${core_path} || /usr/bin/true"
    VERBATIM
)
add_dependencies(modify sign)