function(verify_architectures file) execute_process( COMMAND xcrun otool -vf ${RunCMake_TEST_BINARY_DIR}/_install/${file} OUTPUT_VARIABLE otool_out ERROR_VARIABLE otool_err RESULT_VARIABLE otool_result) if(NOT otool_result EQUAL "0") message(SEND_ERROR "Could not retrieve fat headers: ${otool_err}") return() endif() string(REGEX MATCHALL "\narchitecture [^ \n\t()]+" architectures ${otool_out}) string(REPLACE "\narchitecture " "" actual "${architectures}") list(SORT actual) set(expected armv7 x86_64) if(NOT actual STREQUAL expected) message(SEND_ERROR "The actual library contains the architectures:\n ${actual} \n" "which do not match expected ones:\n ${expected} \n" "otool output:\n${otool_out}") endif() endfunction() verify_architectures(lib/libfoo.dylib)